animalpedia: REPTILE ENCYCLOPEDIA.

Introduction:

All reptiles are truly amazing adaptable creatures,with marvellous body structure.All reptiles are cold blood creatures that means they can't regulate their body temperature,in order to that they need to bask which allows them to regain body temperature & it is proved that doing so will increase the strength of the reptile.Reptiles are the Hallmark for the evolution on the earth as birds are evolved from dinosaurs,even a mammal is evolved from a reptile the earliest reptile took it's birth around 305-310 million years ago.So considering them the godfather of land creatures.Reptiles have developed specifically some weapons like the jaws,size in regarding muscle, no animal could meet crocodiles & alligators. But smaller reptiles has shown more evolution than any other reptiles.There are around 9475 species of reptiles which are distributed around the world except in Antarctica..Modern day reptiles are classified into 4 different orders.

TESTUDINES:It includes reptiles like tortoises, turtles, terrapin.

SQUAMATA: It includes reptiles like snakes,lizards,worm lizards,legless lizards.

CROCODILIA:It includes reptiles like crocodiles,alligators,caimans.

SPHENODONTIA:It includes reptile like the tuatara.

In this chart there are given some reptiles starting off from the dinosaurs on the right side like the triceratops,Pterosaurs along with a transition species of a bird which is called the archyoptryx which led to the bird classification,on the left side we have marine reptiles like the Pleaseosaurs which ruled the oceans during the permian period of the time line which was around 100-200 million years,along with we have modern reptiles on the top of the chart like the snakes which are classified under the order squamata along with lizards,there are turtles,tortoises classified under the order testudins along with the largest reptile the crocodile classified under the order crocodilia there is even another reptiles called tuatara classified under the order sphenodontia.

After knowing this you must know the time line of the animal history,questions like when did the true life was formed when did the reptile first emerged at what age?we are going to discuss somethings list this.

PRECAMBRIAN PERIOD

(5000 million years)

It is the beginning of the geological time line which is a supereon of 3 major eons like the.

Hadean,Archean & Proterozoic.

The climate was very much harsh & there was no free oxygen it was something like this

The new born earth was very hot & could not sustain life slowly from 6 billion years as the time reduced to 4500 billion years earth got to a temperature of 40-50 degree centigrade & slowly life started to began,But how? Is this really possible to form life in such kind of environment.Let us know how did the life began?

As we all know life has begun with the small unicellular organism,what are unicellular organisms? well they are tinest forms of the life which include bacteria & viruses.For the formation of the life first there must be a sample DNA & RNA how did they form?There must be a reason behind it & scientists have found it.The optimum temperature for the formation of the proteins that will code for the formation of the DNA & RNA is around 70 degrees centigrade,below which it will get deactivated & above it will get denatured,Such kind of the temperatures could only be found in the regions near the volcanoes & the hot springs.

The primitive atmoshere has lot of ammonia,methane,lots of hydrogen gas released due to the volcanic eruption.The basic proteins & amino acids are enough to form a single DNA but how is it produced.Precambrian period has many volcanoes eruptions consist of carbon,nitrogen,oxygen & hydrogen interestingly these are the same compounds which form protein a basic protein consist of carbon,nitrogen,hydrogen, & oxygen but to initiate the reaction there must some heat provided this heat is given by the friction of the molecules with the ash which is being produce while eruption.

So,by this process a simple protein is formed which has capability of coding DNA & RNA,don't think it is completed this DNA has to be inserted into a cell for the completion even protoplasm must be there then it is a perfect cell.How did a cell produce for the first time in the history,Scientists concluded that the primitive cell which produced from the energy of the lightnings & the volcanic eruption,this is interesting that we are taking note of abiogenesis which means the life form is produced from a non living thing at first abiogenesis took place followed by biogenesis production of the species of animals or plants from it ancestors or its parents which is biologically existing.

Now a cell is produced,it cannot live in the harsh environment without the help of an extra protective coat & protoplasm,later this was accomplished a cell which has produced protoplasm & a fine protein coat around it & it was waiting for the DNA,after taking in it we have finally got what the true meaning of biology is.Further it has produced some unique proteins which are capable of coding for the reproduction ,the primitive reproduction only included asexual one like the binary fission.

At last we have got some colony of the bacteria,the most primitive bacteria is the archaebacteria.This is formed at the end of 4000 million years.

We should also note that the most primitive element is the zircon which is existing since 4500 million years.

Now slowly different types of bacteria started emerging but these are all just unicellular organism at the end of the precambrian near 600-700 million years a small invertebrate has emerged this has given us confidence that even better multicellular organism are hoping to step on earth.But the free oxygen has already got into the atmosphere by the blue green bacteria & other bacteria forms which are green & help in the photosynthesis & release free oxygen.There are bacteria like chlorophyll bacteria.

Apart from this we have got another evidence of the multicellular life forms in the later precambrian period like the ediacaran this is seen in the ediacaran period.

Geologists have unearthed another plant like animal called the Charnia named after the Charnwood forest.

The the most primitive ferns.

Scientists could not prove it weather it was an animal or a plant because it has got the characters of the plant & animal,it is a stationary & sessile creature which has cilia & flagella for the grabbing of the food particles,so this might be a connecting link or just a mysterious creature which has existed.

The main point that has to be noted is that if it where a plant it has to photosynthesize the food material we might even think that there would be a change in the pigment might be other than chlorophyll, the green pigment which is present in modern plant has very modified pigment & is meant for the photosynthesis under most of the conditions.But charnia was living in the dark ocean bed some where around 1000 feet deep like the picture below.

Charnia lived in deep ocean where the light could not possibly reach then how did it get the food.Scientists & most paleontologists believe that since it is the most primitive animal to ever exist they told the charnia was get its nutrition & food from the water particles most probably by the body diffusion.

Did you every wonder why Charina has got ramified structures like the leaf veins? This is probably because the body structure holds good amount of the body diffusion for nutrition this is simply called the body plan or bauplan. Our body plan is bilateral if we are cut into two by longitudinal section we would get 2 identical halves on the lateral sides.

So their was simple body plan & why their where no complex body parts this is another question where we need to focus on.There is something called the genetic coding we are coded by 64 complex genetic codes but the life on the primitive earth was so simple & it has got not complex in it they found that that charnia was coded by 4-5 genetic code.So that was very simple.

But all of a sudden they have got extinct but how? is the biggest question.According to the researchers there was very huge volcanic eruption all around the world which could possibly the ashes of the eruption covered the entire oceans leaving charnia no option but death.

This is a simple sequence cells-organ -organ system.So there are some very unique animals like the Sponges which are have cluster of cells but they did't grow any organ for further evolution this is because they lack nerve cells which help in the co ordination of the cell to another cell which eventually form organs.

Their body is simple which is formed with cells which are attached by the collages fibers very much found in our body.Each cell is attached to another cells with collages fibers surprisingly the cells of the cells of the sponges have regrowing capacity & attachment of the cell to another cell to form a mass or clump of daughter sponge.

So as the oxygen has finally got into atmosphere & the living forms have started emerging.For new animals & new geological time we need to enter into Cambrian which is the turning point of the life forms on earth.

So after formation of the true life of multicellular now how did the animal go to different places for feeding or exploring the places the answer is simple they have produced locomotry appendages for locomotion the ventral side like the dickinsonia.

These are very slow animal it is like you don't any change in the distance they have covered.Most of the evolution took place while the animals where attached to the ground their moved with their tube feet.

The locomotary appendages slowly changed according to the body this is called the body plan.

We have prehistoric animal like the kimberella which was a molluscan more like snail.

As you can see the above picture of kimberella which have evolved from the stationary or sedentary animals so the locomotion of the kimberella was very slow so slow that we need to speed the camera,so we have got answers for the questions like why is the snail a slowest animal? This is quite interesting thing that the land snail like the helix are the evolutionary fossils which means they have not under gone any change for millions of years.

Compare the basal part of the snail & kimberella they are almost identical except the locomotion is wavey in kimberellla. SO now we have got idea of how did the locomotion began in what kind of animals & the response of the locomotion towards the environment.The locomotion is the one of the best evolutionary aspect how did the animal travel & formed a colony out of it.

There was a progressive increase in the sensory organs in the head which is called the cephalization .This is simple why do you have mouth places below the nose this is simple you need to smell the food before tasting & so does the eyes.

Kimberella has evolved to another animal which has distinct locomotry appendages this animals is called the spriggina which is has long lateral appendages for the locomotion,now locomotion has become one of the common things that has to be added for the evolution of life.

There are still fossilized impression of their animals in Canada & parts of Australia.

We have learnt alot of things about the body plan & the primary aspect of evolution which is discovering new places & taking refuge from the large predators by locomotion

CAMBRIAN PERIOD

The precambrian period is the period where we begin our journey,as you can see the above picture it started during 600 million years where life was defined just a algal forms or bacteria never the less staring from the small is very good we are discussing something which has really happened under the water or Haldane soup ,it is the time of algae where it has gone through evolution from anoxygenic heterotorpic algae which where capable of surviving in the environment where there is was no oxgen as the earth was not consisting of free oxygen or ozone,the formation of first oxygenic algae led to the formation of free oxygen where animals started to emerge as oxygen is a primary thing for a living organisms ,now we have entered a new period called the Cambrian period scientists call it the Cambrian explosion where the first animal began to form it was an invertebrate which was giving rise to new heights of population,now we will be using the word population very frequently.

During this period there was vast diversification of of the Burgess shales across the world,There where many weird creatures that we are going to discuss now their body structure is made as if they are in hurry to thrive in the oceans.

One of them was the Opabinia this was found in the early cambrian period,the most strangest part is that it had 5 eyes this is a big wonder because no other animal on earth have 5 eyes.

As you can see the picture of opabinia it had 5 mushroom shaped eyes,these eyes indeed had many small lens & each lens would form a small part of the image there by juxtaposing of all the images of all the lens in the single eye it could see the entire picture.

Above all it had proboscis to catch its prey might be small invertebrates.The proboscis was very long & thick & could go to deeper parts of the murky soil to catch the prey.During this period animals had to grow shell around them they are made of calcium deposits.The locomotion of the animal was quite interesting it was swimming parallel to the surface of the ground unlike the previous Burgess shales which where creeping on the ground with the help of tube feet which is present to their ventral side.

There are more strange creature in cambrian period like the Wiwaxia it had grown spines on the back of its body,it was more of slow moving animals & was not like opabinia.

As you can see the above picture Wiwaxia was dark in colour & very strange scientists had a dought that are these some kind of the connecting link to the sea urchins because they where just like Wiwaxia.

Compare both of them we find many similarities their body structure is more or less globular & they are surrounded by spine,Paleontologists told that most of the primitive animals depict modern day animals cause they have evolved & evolved to higher animals & that a kind of prof & which we would gradually see them in later parts.

The strangest of all kind was the Hallucigenia why? Because we you watch it very closely you would get hallucination so said the scientists.

How strange is this animal it had leg like spine on its ventral side to walk & spines it back for the protection

Its legs would detect minute vibration in water & there by acting as primary sense organ & head became more distinct,These where found in the mid-Cambrian period.

There where animals with slender bodies & had distinct legs in the ventral side but with out spines like the Aysheaia,till now we have seen strange animal with spines & clacarious shell on their bodies but Aysheaia was quite interesting, it was a defense less animal without any kind of shell around its body & is made of soft tissue.

As you can see the above picture they are slender soft bodies & multi-legged animals.

Aysheaia was remarkably similar to the Onycophoras which are commonly called the Velvet worms.They match Aysheaia in all ways with out any spot.

How is a prehistoric animal like Aysheaia so similar to the Velvet worms the answers is that velvet worms are their descendents & are living fossils that mean they have o under gone any evolutionary changes for millions of years & so velvet worms resemble Aysheaia.These where found in the late cambrian period around 450-400 million years or so.

The invertebrates have flourished around the world mainly one particular animal which became very successful was swimming through the oceans where called the trilobites, these are very small creatures probably the size of a wall nut or an inch long it used to feed up on the small creatures even plankton like the modern krill.

The most successful animals in the history of evolution why they became most successful animals? It is simple they have grown lots of chitin or calcium carbonate on their body which molds the body & strengthen the body & gives support.

Some trilobites have so thick shells around them that it is not possible to pierce any of the materiel.

First true eyes where found in the trilobites but they are made of of inorganic material the same material which is present in their chitin,They have assumed different shapes some where very small but highly defencive & some had long spine to attack or defend from large predators,There are more than 300-500 species of trilobites discovered around the world.

The true shape of the trilobite could only be seen after long duration of carving & removing small stones from the fossil & this would take lots of time & effort.

Here are some of the species of trilobites with different variation.

Some have thick shell around them & highly defencive like the tortoises such species are considerably small because small body will have small shell & big body should grow more amount of the chitin which certainly was not possible with these animals.

Some of them had eyes on the stalk probably they lived under the murky water with eyes pop out of the mud looking for the prey just like the modern rays.

They have eyes homologus to the stalk eyed insect which even have eyes on the top of its stalk.

Some of the trilobites had spines for extra defence like the species below.

Some had thick shell along with spines on their body they just had spines at the front & the rare end like these species.

While some had small led like structures at the ventral side with thick shell on the dorsal site just like the Caterpillar of modern days.

This is all in one piece of image.

But why have these changed so much there must be some kind of the reason,scientists have unearthed another bigger sized animal which they though was the most fears predator of the cambrian so these trilobites have changed so much.

The animal is called the anomelocaris which was bigger than the trilobites,even these creatures where living in cambrian period,as i said the earliest forms where the arthropods which means they have jointed appendages like these creatures.

Though these where small creatures they where predators hunting down small creatures about the size of trilobites,trilobites & anomelaceris are one of the first animals to have eyes,they have compound eyes just like the modern insects,these eyes are made of calcite crystals that means they are made up of calcium carbonate.This is a very interesting thing that earliest creatures where having eyes made of an organic substance which includes carbon in it,Just like the insects anomelocaris had lens in their eyes in insects like house fly there are around 2000 lens in each eye,in anomelocaris had 16000 lens.These eyes give them an overlapping images a kind to blur in humans

It is a fact that the eyes of the primitive animals are protruded out of the body to give a clear vision of the surroundings,but the modern animals have eyes protected inside the orbital bone & muscles this is a kind of evolutionary aspect that has to be noted.

Anomelaceris was the great white of the primitive oceans,it grew to the size of 6-7 feet in length which is very big in those day just like the whale shark in the modern era.

The fossil proved that it had large mouth on its ventral side which capable of creaking most of the things.

Now do you remember why the previous animals like the Opabinia which was very much agile & why wiwaxia & hallucigenia produced spines around the body it is just because the anomelaceris was fears predator which prey on most of the animals including them.

But there is one thing that scientists could not prove is the sudden diversification of the animals through out the world scientists call it the Cambrian explosion.The sudden explosion of the animals without any common ancestor is very distinct feature of the cambrian but this could not be answered.It is like reversing the darwins flow chart of the animals,the chart includes many ramification which no common ancestor but the cambrian explosion it exactly reverse to it.

While this was going there was another animal for which we need owe ourself this animals is called Pikaia.

This is a mediam sized animal which has led to new class of animals called the VERTEBRATA slowly fisges have emerged from it then the amphibian we would gradually study how did they got evolved from different animal & what are the transition species.

The animal had pseudo vertibrate which eventually gave rose to the vertibrate animals & it swimmed with fins .

We have some 30 genera of animals with out any common ancistor,we have got trilobites & even yunnanosaurus.

This has been a great mystery for the scientists.

ORDOVICIAN PERIOD

These are little hunters with a shell on their back now that we have an idea of cambrian period let us go for the next it is called the ordovician period in this period trilobites where most common animals,there are even some new species added to the competition of trilobites these sea creatures are called the Nautilus, these are small shells which have completely spiral shell & an opening on one side thought which it's tentacles protrudes out by which it grabs it's food most of the food it was eating is small meat particles because of the earliest digestion system was not developed so well.

along them there are also conodonts (phosphatic fossils with a tooth-like appearance) found in sequences of shale, limestone, dolostone, and sandstone. In addition, blastoids, bryozoans, corals, crinoids, as well as many kinds of brachiopods, snails, clams, and cephalopods appeared for the first time in the geologic record in tropical Ordovician environments. Remains of ostracoderms (jawless, armored fish) from Ordovician rocks comprise some of the oldest vertebrate fossils which where unearthed by the scientists or paleontologists.

SILURIAN PERIOD(golden age of fishes)

Now we are going a head in the time line now we are in the silurian period where natiloid shells became common,apart form that this period is birth period of fishes where new species of ocean creatures where added for the computation,during the silurian period the temperature rose by 50-80 degrees centigrade this is very high temperature for land animals to with stand hence theire where new species added in the ocean itself,there was a continued proliferation and expansion of the brachiopods, and the oldest known fossils of coral reefs,during this period large glaciers where melted into water and large amount of water is added to the oceans along with this there where also moose & few plants on land with xylem & phloem this was given off by algal members ,as it is the golden age of fishes,fihes ruled the oceans as trilobites and other small invertebrates where having hard shells in order to feed on them fishes first produced jaws & teeth doing so they became the first animals to have jaws or teeth and famous of all the a placoderm called dunkleosteus this was a fearsome predator which many use to feed up on the trilobites & other small invertebrates.

As in the picture dunkleosteus(right) had a 'V' shaped sharp dentation just like the modern sharks(left) their dentation is almost silmilar,with those hard jaws dunkleosteus gave devastating bite which had a bite force of collosal 1300 pounds while the bite force of modern shark is about 670-700 pounds.In this period placoderms became very common fishes which where relatively larger & stronger,during this period a fish which had few fins was evolved into a fish with higher organs and few other fins added up like the pectoral,caudal fins etc.The formation of fishes is our first hope of life on land as these fishes where evolved into amphibians.

Now we are going to learn a new term called transition species,this is nothing but a simple animal which holds the link between 2 different species like the fish & the amphibian or dinosaur & bird.But we are more concern with the transition specie between a fish & an amphibian.

DEVONIAN PERIOD

During this period a new species of animals where emerged they are called the amphibians which are godfather of all the land animals,so how did a fish evolved into an amphibian?.We are now speaking only regarding a group under the fishes called placodermi.

As said before silurian period was the golden age of fishes & even said that it was very hot period where even fishes could not stand a chance against the temperature how ever scientists believed that the hot temperature led to the early drought of lakes,rivers etc.Fishes where the primary animals which where suffering during a course of time this droughtification of rivers & lakes where responsible for the formation of lungs in the fishes which was a final & permanent answer for the hot temperature.now a new transition specie was evolved this is called the celacanth which are lobed fin fish showed the signs of formation the limbs like the legs & arms.Since formation of lungs took place there was no place in the water for it a brave amphibian took it's first step on the land this specie is called as ichthyostega picture below

( artistic image of ichthyostega)

(a celacanth)

Scientists have uneathed a secreat regarding Celacanth as it consist of smll limbs which where growing in size,like the lobes on the fish these where grown so big that it has gone bod modification and gave rose to amphibians which had flippers on their foot which is a common factor in salamanders,this amphibian step it's foot on land as the temperature was very hish it's soft & mucus skin was not subjected for such kind of temperature so what happned evolution took place.

CARBONIFEROUS PERIOD

The most intresting thing about this period is that it the golden age of REPTILES , now this amphibian which has a soft,tender & mucus skin has lot of problems getting on to the land though a promenent legs are formed,it has to replace it's entire skin in such a way that very few percentages of water shall be dehydrated from the body as of the amphibian which had sof t& mucus skin which is more succeptable to the water loss as it used to live in the water,at this stage this amphibian has changed it's bodily skin into scales which minimises the water loss and hence a new animal in the history was born they where called the reptiles.This animal gave rose a new species of reptile called the Proterogyrinus which is a reptile like amphibian,it's body showd signs of sclaes & very few parts with soft skin may be Proterogyrinus is a connecting link between an amphibian & a reptile this is considered as a transition species

As u can see in this picture Proterogyrinus where reptiles showing amphibian behavior some what like a modern crocodile which are hydrophilic species of reptiles.Formation of one of the first animal like reptiles gave us the hope that there where even other animals which is led by this reptiles.Now these reptiles began to dominate the planet earth which gave rose to many small reptiles which where moving on their their four legs just like a lizard,it also gave rose to smaller specie of reptiles which sbegan to stand on their 2 hind limbs and tried to walk these became succesful and gave rose to dinosaurs.

One of the earliest reptile is the Hylonomous which lived during the period of cretacious around 312 million years.It was one of the earliest lizard that eveolved into higher reptiles that mostly dwelled on the trees to get protected from the predators.

PERMIAN PERIOD(golden age of sail back reptiles)

The reptiles in this period where responsible for giving rise to new species of animals called the mammals & the dinosaurs,as said before reptiles where categorised into a 2 the the reptiles with which where moving on their four legs which are called the tetrapods & the reptiles which began to move on their 2 hind limbs thecodont this name comes from the thecodont dentation which is primary used for the animals with the socket teeth where the teeth are placed in the persistant cavities called the sockets which allows the animal to produce more bite force.The tetrapods which where also called as sail back reptiles like the dimetrodon & pelycosaurs.Pelycosaurs includes reptile like mammals which lived during premian period & gave rose to mammals.This class includes the famous glypdon which is seen in the movie ice age.

The above picture of a gluptodon,this is believe to be an ancistor of modern armadello as you can see in the picture.

Dimetrodons gave rose to a new group of animals called the mammals like us & the thecodonts gave rose to the most brutal animals to ever step on the earth they where the dinosaurs,along with that it also gave rose to the birds & pterosaurs.The real evolution begins now how did a cold blooded reptile like the dimetrodon gave rose to mammals which are warm blooded animals along with hair?

The dimetrodon was not directly linked to the mammals but these indeed gave rose to the another kind of animals called the therapsids this group of animals are advanced synapsids,now what is a synapsids?

All the animals are classified based up on the number of holes in their skulls like as follows

SYNAPSID:- THEY HAVE 1 HOLE IN THEIR SKULL PRESENT ON THE TEMPORAL REGION

eg:- all the living mammals & their ancystors are synapsids a)it is the skull of cyanognath b)homo sapian

DIAPSID:-THESE ANIMALS HAVE 2 HOLES IN THEIR SKULL

eg:-most of the dinosaurs like the giant T-Rex are classified under diapsids.

ANAPSID:-THESE HAVE NO HOLES IN THEIR SKULL

eg:- all testudines(turtles,tortoises,terrapins)

ALMOST A MAMMAL

So the therapsids are advanced synapsids with one hole in their skull,they which are the real ancestors of mammals,these where walking on four legs & where looking just like the dogs & capybara.

The above picture is a cyanognath called the dog toothed animals which lived in the late permian are mammals,their body is covered by thick hair & the lactation began which me they slowly produced the distinct thing which represents a true mammal like the eutherian(placentate mammals),they produced milk for the first time in the dinosaurs timeline along with having tooth fixed ready to strike just like a dog enables the access to the mammals.

Now arose a kind of the class called monotremats during cretacious period,these are half mammal & very few characters of the reptiles are also seen like the ability to lay eggs & having an interclavical bone which is only present in lower group of organisms like the reptiles & amphibians.

Steropodon is one of the earliest ancestor of the platypus which lived in late Cretaceous period which is around 100 million years,there is even another ancestor by name kollikodon

These have mammalian characters like the hair on the body,the behaviour is just like mammals even the parental care,even mammary glands are present but without nipples this is because reptiles don't have mammary glands,these animals produced mammary glands but nipples still didn't grow so is could not develop the method to deliver the milk,due to this reason they lay eggs & the amnion gives the nutrition to the growing embryo.There is even the change in the texture & the structure of the egg also changed.Reptiles have the leathery shells they bend flexible this is to prevent the death of the embryo even in harsh condition like the water flow from these kind of eggs they have changed to bird like eggs take a look at the below picture.

This is a great evolutionary break through for the evolutionary forms like the steropodon which led to the new kind of modern skillful creatures called mammals.

First the fishes where seen in silurian period later insects which are the first land creatures & even first creatures to take flight which came in early devonian then came the amphibians during late devonian then came reptiles during carboniferous period in which few evolved into sail back reptiles & gave rose to mammals at last came the birds,rulers of sky.So we can say that birds are most recent creatures in timeline scale.These are interesting creatures,want to know hoe interesting?

For that we need to move a head in the time line & now we are going to enter a whole new era called the mesozoic era which is where the earliest dinosaur where born & the end of that period was mass extinction of dinosaurs.

MESOZOIC ERA

This era is divided into 3 periods like the triassic which was around 200 million years,the jurassic which was around 150 million years old & the last is the cratecious period or mass extinction period was around 100 million years ago.

In this era North America which was a Paradise of dinosaurs was connected to the South America by the volcanic action when the lava became cool it formed a big fertile land which eventually connected north to the south,now the dinosaurs began to move from one continent to another during this migration very few species rays was extincted due to new climatic change & the hurdles.

So we came to know that thecodont gave rose to dinosaurs,ptersoaurs where close relatives of dinosaurs as even they have emerged from the thecodont ,these are first animals to take flight.

Permian-Triassic Extinction

The most devastating & the biggest catastophy ever to happen on earth is the permian-triassic extension then comes the K-T extinction where dinosaurs have vanished.

The catastrophy was so massive that there was the largest amount of the exitinction of the animals,Around 95 % of the sea creatures got extinct we now know that the early life forms where more in water than on land,so we can imagin how many animals got extinct,70% of the land creatures got extinct.It is also known as the largest insect excintion,Through this earth could not cure itself till 10 million years later.

Trilobites which where very abundant lost their race through this extinction 100%

Followed by echinoderms & sea scorpion also got 100% extinct.

There was a left over race of cephalopods(octopuses),Brachiopods,Gastropods & few bryozoans.

How did this happen? Scientists have told that there was repeted bolide(bright meteriods) strinkings on the earth trigerring a perfect chain reaction which initiated huge volacons to erupt & massive earthquacks which have left their trails as fissures,volcanos produced most of the carbon-di-oxide which is very dangerous to smell & has adverse affects on the body.

Sea creatures have died the most because there was nothing to stop the volacanos in the water which released some deadly chemicals which soon spread the entire ocean to leave nothing except but the dead bodies of the animals.

PTEROSAURS

These are big animals which where close relatives of dinosaurs,they resemble modern bat with 3 fingers & thin sheath of connective tissue running from their legs to their arms,very amazing creatures.These where the largest animals to take flight on the on the earth with around 40-45 feet wingspan & bigger than a giraffe while standing,there are many species of pterosaurs with some spicies gigantic & some species smaller,some of them had big head they are found in wide verities.

Though pterosaurs where gigantic animal which had the power of flight they fed on fishes as you can see the picture most of the time pterosaurs spend catching fishes they directly depect modern fishing birds most of the costal birds like white tailed fish eagle feed on fishes,Pterosaurs are social animals which has to migrate for their reptroduction of all these species quetzalcoatlus was the largest & had a wing span of 45 feet.These animals also walk on land but for a few distance, lifting their body off the ground was not a tough buisness because they have small bone which where built for flight they had strong muscles on their chest or keel to give the power of flight especially the initial lift.

BIRDS

Birds the sky kings ruling skies from cretacious,all modern birds are dinosaurs why they are direct descendeds of dinosaurs,so how did a cold blooded dinosaurs become a ruler of sky!

As we have learnt that birds fall under theconds & direclt derived from dinosaurs,now you need to know about the new dinosaurs called the feathred dinosaurs.These dinosaurs has feathers on their scales looking just like a modern bird but with out the power of flight,one of the dinosaur used to live in very cool place since dinosaurs are cold blooded they can not regulate their body temperature in regards to their environment .so, it can came up with an idea what is it?,it produced feathers on it's scales for insulation for prevent the exit of body heat & hence it regulated it's body temperature in this way.Dinosaurs never produced feathers for flight in the first place,velociraptor was considered to be the first feathred dinosaurs.

So as you can see in this picture velociraptor never had the power of flight it's bones where non pnumatized without hallow spaces in the bones unlike the modern birds which have the hollow bones,this velociraptor desperatly wanted the power of flight because of the natural calamaities like volcano & earthquacks there shold be some way to escape from these things so it took advantage of it feathers & started glind from tree to tree,slowly evolution took place & then a new transition specie was born called the Archaeopteryx which is the intermideat form between a feathered dinosaurs like the velociraptor & the modern bird with power of flight like the falcon,archaeoptryx had the power of flight so the dream of velociraptor has come true the real power to fly.

ALMOST A BIRD

Archaeoptryx fossil created revolution in the history of paleontology,the fossil was found in germany,after many keen check ups this was considered as the missing link between a dinosaur & a bird.As you can see the picture almost all feathers are very well devoluped like in the modernbirds,their primary feathers streatched longer for the inital lift like in eagles in the right u will be finding similarities like the hight to weight ratio of archaeoptryx is almost to that of an eagle.There may be many feathered dinosaurs but archaeoptryx was the only one to fly this is a 2 feet bird,mostly tree dwelling & became extinct in the same way as the dinosaurs got.There may be very few transition species but with out them evolution would not be continued.

The evolution of the bird from the dinosaurs has an interesting evidence which is given by few scientists how have done extensive research in the evolution of the bird,they have taken scale genus & feather genus from respective parts of the body,now the feather genus have being inserted into the scaly part of the birds body that is it's legs,supprisingly the bird grew feathers even on the leggs that is a meracil & a big out come for the scientists,they have proved that the feather genus is a superrior one when compared to the scale genus,that is what happned in this case they have inserted feather genus & the bird grew feathers even on the legs.some times this even occur rarly in wild like the progeria in humans.

A part from that we need to know the skeletal systam of the bird though a bird might have a wing supported by muscles but inside there are finger which can't be seen.

As you can see the above picture even birds have fingers embedded in the muscles & tissues but this may be seen in the modern birds like the hoatzin in which the finger & the claws are clearly visible we have already noated that for every change in the nature there will evidences like the transition species.

We have toxic birds like the hooded pitohui & the Little Shrikethrush,we might wonder how did they get this toxic nature interestingly we have even got toxic feathered dinosaurs like the sinornithosaurus.

As you can see the above picture sinornithosaurs had venom in its wings just like what modern birds like the hooded pitohui has.Every thing in this world has got links & ancestors except for the cambrian explosion.

DINOSAURS

A new animal was born during triassic peroid which was the beginning of the brutality on earth,in this perod birth of dinosar took place from it's ancistor thecodonts,They lived in 3 different periods.the trissic is the birth of dinosaurs which is around 200 million years,jurrassic is the period where dinosaurs ruled the earth which is around 150 million years & the last is cretacios period where mass extinction of dinosaurs took place.

Dinosaurs got so giangitic that no animal can match its lenght even in the moder era.there are dinosaurs which had grown up to 175 -200 feet in length like the Amphicoelias fragillimus

The above picture of an amphicoelias fragillimus a very huge dinosaurs what made this dinosars so huge?why have the carnivorus dinosaurs where small with lng teeth? let us focus on it.

All the dinosaurs are divided into 2 major types namly a)Theropod b)saurapod

THEROPOD
(beast footed)
These are the group of carnivorus dinosaurs which live in cenozoic period where responsible for the brutality on the earth,the largest theropod was the spinosaurs which is around 45-50 feet in legth or even bigger accourding to few scientists.

As the picture above spinosaurs where very huge theropods i mailny live near oceans & sea just like a water dewller the main question is how did the animal become so large if it where a water dweller,many scientists even think now that a big creature like the spinosaurs fed on the fishs how ever this questions is a mistry one but moving on to the other species of theropods like the T-Rex which is the most famous of all,even few scientists believe that these creatures are scavengers though they are the secong largest theropods around 40 feet in legth .

Even this large predatorus dinosaurs had to under go evolution durin triassic period which is around 200 million years T-Rex was not in this size most of the dinosaurs got evolved from their early ancistors which where very small like T-Rex has evolved from a dinosaurs called guanlong like the picture below.

As you can see in this picture it is already in the shape of T-Rex it grew size as nature became harsh & violent,the fore arms arebigger for guanlong but for the T-Rex the arma are no less then few centimeters they are very small when compared to guanlong,T-Rex never used it's fore arms except for copulation during mating a male would screatch female back with those arms except for that it has being used.

As far as theropods are concerned these are large carnivorus animals with largest claws to ever have on the earth,Their exoskeleton cosist of very hard oseoderms which are bony plates,large dinosaurs have developed from its smaller species,as said before theropods are diapsids with two holes in their temporal region of their skull.

Several characters that typify a theropod: hollow, thin-walled bones are diagnostic of theropod dinosaurs. A jumbled box containing theropod bones (from the UCMP collections) is shown at right. The hollow nature of the bones is certainly more obvious in 3D, but you should at least be able to make out the general tubular structure of the bones. Other theropod characters include modifications of the hands and feet: three main fingers on the manus (hand); the fourth and fifth digits are reduced; and three main (weight-bearing) toes on the pes (foot); the first and fifth digits are reduced. Most theropods had sharp, recurved teeth useful for eating flesh, and claws were present on the ends of all of the fingers and toes. Note that some of these characters are lost or changed later in theropod evolution, depending on the group in question.

To be a climax(apex) predator you need to be either large like saurapods or have teeth & claws so big that they are virtualy not created like the theropods even,theropods where very small dinosaurs during triassic period to compete with others it had to become larger & larger until they excel their competators some smaller species like the Deinonychus antirrhopus though this dinosaurs where small they have developed such a brutal killng mechines,they grew their claws big & killed animals without mercy.so we have come to know that a dinosaurs had to excel in some or the other way to be in top of the food chain.

As the picture abouve Deinonychus is a featheres dinosaurs,paleontologists believe that these feathers are not grown for flight but grown for isulation.

SAUROPODS

All the herbevorus long necked dinosaurs are classified under the group sauropods,They never had limit for their growth might be these dinosaurs where twice their length if they where still living.These first appeared in the late triassic period they become more common & wide spread during jurrassic period of 150 million years,the earliest Sauropods of triassic period where smaller to the sauropods in the jurrassic period,as the carnivours became more aggrassiv & brutal killing mechines they have no choise to exced in one of the other way or get their rays extinct,so these sauropods grew their body size so tremendusly that they are climax herbevorus animals which means they have no predators in wild which is now not possible because all herbivorous are been eaten by carnivours animals as a part of food chain.

If we think of sauropods the first aniamls that strike is the brachiosaurs,diplodocus, & even more,they have their knee joint just above their foot just like the modern elephant.As we go further into classification most of the dinosaurs of triassic period where classified under the family titanosaurs which includes even argentinosaurs.

These creature are very massive their neck alone can grow up to 30-40 feet or even more.Even though these creature are very big but still they hatch from an egg bery small their growth rate is almost 15-20 times greater to elephants,

Sauropods had small teeth that could only feed on the leaves of the tall trees,the creatures cannot sit & sleep hence they sleep in standing position,their stomachs are one of the biggest on earth with many bacteria & small colony of fungai,this is because animals cannot digest a starch compound called cellulose,hence they are in symbiont associate with the cellulase bacteris which diests cellulose of leaves just like moder herbevorous.

As abouve picture of a saropod skull their all teeth are similar like it is monodentation that means they have similar kind to teeth,these where very poor when compared to theropods.As said before even these are diapsids we can see 2 distinct holes on their temporal region which occured in late cretecious period.

Sauropods where social creatures just like the modern elephants which live in groups,how ever these creatures geans where not passed to next generation due to mass extinction.

In the above listed squamata is the most diversified group of reptiles which are around 9150 species & even more are discovered in last few years & the least diversified is the sphenodontia because this group consist of tuataras which are only 2 species existing,they are around 40-50 species of it's kind but during the course of time they have been vanished the only species of it's kind is living in new zealand.

CROCODILES & BIRDS(Archosaurs)

In this era we come across the dinosaurs which connects the birdsto crocdiles,seems interesting crocodiles & have similar skull to that of birds not other group of reptiles this might be a big superissing thing,this is because the crocodiles have emerged from the same ancestors as the birds did we already noated that the dinosaurs grew feather not for the flight but only for the insulation since they are getiing insulated there is no need of the having cold blood so they became homeotherms unlike other reptiles.

We have a prehistoric animal called the Euparkeria this was responsible for the formation of new animals like the crocodiles & birds.

This gave rose a new specie of its kind this is called the archosaurs thes are average sized dinosaurs which are around 4-5 feet.
Here is the flow chart & you can under stand it very easily.

This is how crocodiles & birds have emerged they both have diapsid skulls.

Now we need to move our journey to the next extinction.

K-T EXTINCTION

This is the second largest extension after the permian-triassic extinction.K-T means cretacious-paleogene.Paleogene is a part of cenozoic era which is the begening period,It is the same how the permain-triassic extinction took place,the same way but this time even dinosaurs have got to their knees.This is why we can live on earth peacefully one of the great advantage.

EVENT
We all know that the dinosaurs did got extinct with the metiroid,but how can a metioroid roughly a size of nearly 15-20 foodball grounds can kill the most dustructive killing mechines on earth,lets find out.

So, long a ago a mteriod struck our planet which wiped out the dinosaurs this we call it K-T extinction.A big metroroid probably it was dinided & sub divided into many particle each particle was a size of small foodball ground as this was in the tail region there was much bigger one a head

As you can see the above picture there are many small particles begind the larger one this is one of the reason,further more after striking the ground it triggered a chain reaction there was continues eruption of the volcanoes & the earthquacks where very distructive all the place around there was just the killing smog of the volcanoes & the hot gases which where emerging out from the fissure of the earthquack,the same was with the seas & oceans too vents brock out erupting plumes of hot gases which combine with the water to produce deadly chemicals which killed most of the sea creatures

It looked something like this a very big crater.

A wide range of species perished in the K-Pg extinction. The most well-known victims are the non-avian dinosaurs. However, the extinction also hit other terrestrial organisms, including mammals, pterosaurs, birds,lizards, insects, and plants. In the oceans, the K-Pg extinction devastated the giant marine lizards (Mosasaurus), plesiosaurs, fish,sharks, mollusks (especially ammonites) and many species of plankton. It is estimated that 75% or more of all species on Earth vanished. Yet the devastation caused by the extinction also provided evolutionary opportunities. In the wake of the extinction, many groups underwent remarkable adaptive radiations. Mammals in particular diversified in the Paleogene, producing new forms such as horses, whales, bats, and primates. Birds, fish and perhaps lizards also radiated.

(Ammonite one of the cephalopod)

(mosasauras largest merine reptile)

The whole bioshere was down there was no meaning in the adptive radiation among animals,This is second most devistaing even on earth.

CENOZOIC ERA

Now comes a new era called the cenozoic era with an eon of phanerozoic,This indeed has 2 periods like the Tertiary & the Quaternary.

Tertiary indeed has 2 periods like the paleogene & the Neogene.

PALEOGENE

Paleogene is the first period of the coenozoic era & it has 3 epochs,this is major period of the mammals & higher evolved species.

Paleocene,Eocene & the Oligocene are the 3 epochs of the paleogene.

The true climate has appeared like the tropical climate along with true land plants which have xylum & phloem.

Mammals got diversified they grew as large as bear.

PALEOCENE

It lasted from 65-55 million years after the extinction of the dinosaurs.Most of the flora & funa was affected in the paleocene due to the K-T extinction.

The extinction did not affect small & borrowing animals which are shrew like animals.These animals have evolved into larger & larger mammals.One of the example from the genes pantodonta which includes barylamdaus animal of the north america.

As you can see the above picture of barylambda which has a shear size of the bear.

We know that insects are the first land animals & th first animal that can fly,by the time of paleocene ants got diversifiedd the planet.

Mean while North America & South America have combined due to the heavy volcanic action near that reagon we still have lot of volcanic activities near that region.As they both have connected animals have started moving from south to north & north to south there was a vast change in the animal species & one of the first members to hit south america are the shrews & recoons.These little animals are very succesful animals.

The migeration continued & we shoud move on to next epoch called the Eocene.

EOCENE

It is the time that saber toothed cats have emreged out from it's cages,They got diversified very much that they became the apex predator,They started ruling North America with it's giant canines.

The true feline predators really powerful animals,Most of the specie lead a formidable life style except for few specie which chose to live with their mates.

They are very big & heavy builded cats,heavier than the modern siberian tiger.

They weigh a lot but saber toothed cats have exel them in terms of power & weight,Saber was not afraid of anything but only one it is called the Terror bird.

The name itself says terror it is a 8-10 feet fiant bird just like the ostrych but it is predator it hunts its prey by knocking them down with it's beak not only saber but many herbeverous animals like the horses of that time have fallen prey to this bird.

This is a large flightless bird which has a very big skull which protects a small brian,look at the shear size of it's skull beside the human skull when compared to modern chicken skull.

Eocene was the last epoch for the Miacids which are the carnivours ancistor of the mammals,they gave rose to new oder called carnivora even in mammals.They where probably the size of a pangolin & had undeveloped skull which is a drawback for the carnivor animals,Most of the carnivor animals have heavy builded skeletal systam except the bird of prey.

During this period birds have got diversified,there where many birds including parrots,macows & the bird of paradice.

OLIGOCENE

It is a geological epoch which is present in between Eocene & miocene,it is also the last epoch of the the paleogene era.This is a signeficant epoch which has the transitional stage from the eocene to miocene.It extents from 33 million years to 23.8 million years.

This is an epoch which is very important for the formaition of the new type of the tropical forests & nature.Oligocene is a greek word which means few new,that means there where diversification of few new animals & plants around the world.

During this epoch all the tectonic plates have being drefted apart & the countries are becomming more distinct like the modern globe,antercitica was drifting more & more.

One of the diversified grass eater where the toxodon which are the ancestors of the rhinosaurs.It looked completely like the rhinosaurs it lead a semi aquatic water life style.

They lacked hornes but scientists have put their theories in front saying that these horse where grown later for the defence from the brutal carnivorous or for the sexual attraction,cause males tend to have bigger hornes than females which is used as attraction.
Apart from this South America became distinct exoctic animals like the tapier like mammals & mammals like the indricotherium became more diversified.

As you can see the shear size of this animal it stood 28 feet in length & weighed more than 19 tons,it is the largest & tallest mammal ever on earth it was larger than the mammoth.Most of the grass eaters are very large like the sauropods.



                                                                             NEOGENE
IT is a new era which is after the Paleogene,it inturn has 2 epoch like the Miocene & the Pliocene.
This era extented from 25 million years to 1 million year.In this era we can see the gradual changes which lead to the formation of the modern earth.Driwfting of the tectonic plates & formation of the major mountains where key for the formation of the good biosphere.

Miocene

Mountain building took place in western North America, Europe, and east Asia. Both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in the North American Great Plains and in Argentina

During the later Miocene mammals were more modern, with recognizable dogs, raccoons, horses, beaver, deer, camels, and whales, along with now extinct groups like borophagine dogs, gomphotheres, three-toed horses, and semi-aquatic and hornless rhinos like Teleoceras and Aphelops. Islands began to form between South and North America in the Late Miocene, allowing ground sloths like Thinobadiste to island-hop to North America..

Pliocene

Alligators and crocodiles died out in Europe as the climate cooled. Venomous snake genera continued to increase as more rodents and birds evolved. Rattlesnakes first appeared in the Pliocene. The modern species like the american alligator, having evolved in the Miocene, continued into the Pliocene, except with a more northern range; specimens have been found in very late Miocene deposits of Tennessee. Giant tortoises still thrived in North America. Madtsoid snake were still present in Australia. The amphibian order Allocaudata went extinct.

Now that we have learnt the origin & the evolution of the life i hope this might be the basic foundation for the students across the world.

DINOSAUR AND PRE HISTORIC CREATURES.

All dinosaurs are cold blooded creatures.

All dinosaurs are covered with scales on their body.
The study of the dinosaur fossils is called PALEONTOLOGY.
There are 3 main periods of dinosaurs called the Triassic, Jurassic, cretaceous.
Ankylosaurs are the only creatures with a bony eyelid.

The largest carnivore dinosaur is the Spinosaurs which was about 50 feet.
The most deadly creature ever to exist is the T-Rex.
The bite of a T-Rex is about 8000-10000 pounds/inch on the other hand the bite force of human beings is about 30-32 pounds/inch.
Amphibiens gave rise to dinosaurs.
Helicoprion is one of the strangest shark.

Most of the evolution of smaller animals is due to deadly land dinosaurs.
Whales would not have been evolved from a small wolf like mammals without a fearsome dinosaur.
Dinosaurs appeared around 300 million years ago.
The first ever bird fossil found was the ARCHEOPTERYX.
Early dinosaur’s birds did not have hollow bones & so they could not fly.
In an experiment scientists grew feathers on the scales of the bird which could explain the birth of bird from dinosaurs.
The largest claw of any dinosaurs was the spinosaurs claw which grew about 5 inches or even more.
During Jurassic period crocodiles where small lizard like reptiles on the ground.
The largest dinosaurs ever to exist the amphicoelias fragillimus which was about 175-200 feet in length.

The largest animal to take flight is the Quetzalcoatlus which had a wing span of 45 feet, it was taller than a giraffe while standing.

Triceratops is the only dinosaurs which had a ball like structure in the place of neck allowing them to rotate their heads & piercing with their horns.
The descendent of the rhinosaurs was the toxodon

It was the late Triassic period when the large T-Rex was evolved from a small dinosaur called guan long.
A part from mammals only dinosaurs and the birds where highly social.
Dinosaurs close their eyes by shutting their lower eyelid unlike mammals closing their eyes with upper eyelid.
All dinosaurs’ lay eggs from small too big.
The first feathery dinosaur was the velociraptor.
Sarcosuchus was a 40 feet giant crocodile.

28. .Pterosaurs had a beak which was 5 feet long, but modern pelicans grow their beaks about 1 foot.

A T-Rex roar can be heard up to 30-35 kilometres.
Embryos of human being, bird, dinosaurs have same features like a tail, teeth in birds.
A dinosaurs DNA was found to be present in the mosquito which was trapped right at the centre of the amber (stone).
Longisquama is a rare dinosaurs to have the logest & most strangest spines on it's back but the function is still unknown.

All carnivores’ dinosaurs are classified under theropods.
All herbivores giant are classified under sauropods.
Mossosaurs was a 60 foot giant marine reptile which draged sauropods into the water.
Megalodon was a 70 foot giant shark.

Dimetrodon is less reptile & more mammal. All reptiles including dinosaurs have excellent sense of smell.

The largest snake to ever exist was the titan boa which grew 40-50 feet in length which was 3 feet wide.
Sharovipteryx is one of the rarest dinosaurs to have wings on it hind limbs

The function of the plates on the back of stegosaurs is still not known, however some palaeontologists believe that it was used in radiating heat.

Terror birds are so large that their main course of diet included horses.

The largest frog to ever exist was the beelzebufo (prehistoric) which was around 2 feet or more.

The largest bird to ever exist is the Argentavis which lived around 6 million years ago & had a wing span of 25 feet.

The largest mammoth was the Songhua river mammoth which was around 20-23 feet while standing
There is a transition specie between fishes and 4 legged tetrapod which is amphibian called Itchyostega.

The largest mammal which ever lived on the earth was the Indricotherium which was around 30 feet while standing.

Jaekelopterus was a giant 10 foot sea scorpion which lived in fresh water.
The earliest Ape called luci was thought to be around 8 feet in length.
According to Sir Charles Darwin due to the hot sun of the Silurian period, there was early drought in the lake so fishes force fully developed lungs & stepped out of the lack as a amphibians.
The Giant
Velociraptor had its wings even on its legs, hence they are called the rare 4 winged dinosaurs.

The largest centipede to ever exist was the artheropleura.

The largest bear to ever exist was the cave bear.
The largest big cat to ever exist was the American lion.

SQUAMATA(most diversified reptile group):

There are about 9150 species which include 2700 species of snakes & remaining 5700 species of lizards.This group also consist of leg less lizards.These are the most diversified group as they are also found in cold places like greeanland,island where temperatures may go down as much as -15 degree centigrade,hot deserts like the sahara,namibia where temperatures rise about 50 degree ccentigrade.

They show very incridible adaption to their surroundings,lizards are the first reptiles to produce venom glands and succesfuly inject it into the prey.

SNAKES

Snakes are the ultimate slithering animals that dwell like no other animal,they are found in extreme

locations. snakes are found everywhere under the water,underground,slithering on the land,even living in the canopies of evergreen forest,they are even found in the arctic circle.They are perfectly adaptable to extremely hot deserts.There are over 2700 species of snakes living all over the world except Antarctica,Greenland,Newzealand and Ireland.The size may range up to 8 inch like the thread snake & sizes up to 50 feet titanboa.Most of the people in the world consider snakes as a cause for the death of the person,but of the 2700 species snakes only 500-600 species of the snakes are poisonous,among these 230-250 species are dangerous to human beings.Most of the Scientists consider snakes as painted tubes.There are over 19 different families of snakes,among that only 3 snake families are poisonous,they are Colubridae,Viperdae,Elapidae(cobra family),among these Colubrids are most diverse.the study of snakes is called as ophiology or herpetology(including reptiles & amphibians).ophis=snake,logy=knowledge derived from geek,herp-slithering ology-knowledge.

colubridae:vine snake opening its mouth in defense

Viperidae:yellow eyelash palm pit viper locking its eyes on prey in amazon.

Elapidae:female cobra with her juvenile cobra

Other families include pythonidae,boidae,uropeltidae(shield tailed snake),Xenopeltidae(sunbeam snakes),

Evolution of snakes:

Its never been technically proved the evolution of snakes but most of the scientists do believe that snakes are evolved lizards,there are few evidences which tell us that a snake is evolved from the lizard,like the spur of a Boa constrictor which is present in the pre anal region .But unfortunately these aren't used for locomotion,they are only used during copulation helpful in fertilizing eggs & found in males.Few scientists even believe that these are modified scales,paleontologists like xu-xing of china found many fossils which might be the possible link between snake and lizard.

There are few primitive snakes which even live now,which shows the character of lizards like blind snakes,borrowing snakes,thread snakes.There is a major group of family called as legless lizards these are lizards without legs,they are found in Asia, Europe,Northern Africa this is a major link between a snake & a lizard.Families like viperidae,elapidae are highly evolved snakes,Speaking about their body they have 200-300 ribs on average.The snakes venom is nothing but an extra strong digestive juice,Scientists call venom as its saliva it took millions of years for the formation of venom.

How evolution took place

As it is been proved that snakes have evolved from lizards,There is some thing you need to know about the venom glands was not a part of snake instead it was a part of primitive lizard.As they are smaller species than most of the terrestrial animals they need to compensate their strength with others & so lizards produced venom,so lizards are the first modern reptiles to have venom.As the lizards was well feeding it got larger & larger,At this state it's legs became useless & so there was a prominent degeneration in their legs.A new snake was born,scientists have unearthed a secret which made most of the herpetologists astonish & that was the absence of fangs.Yes,the most primitive snake had venom gland but there was no means of delivering the venom.

From here on we get to know about 2 different categories one is that which was patient & slowly started growing fangs in order to deliver venom while the other case is that few snakes have given up in evolving venom since then they have started killing it's prey by brute power by constricting it's prey to death,these have lead to degeneration of the venom glands which is used to have previously &this group of new family is now classified under the family BOIDAE(all constricting species).The species which have evolved fangs now started refining their venom in terms of potency.

The species which feed on small & weak prey items their was very little increase in the toxicity of the venom when compared to the snakes which feed on large & deadly prey.For instance let us take an example of inland tipan which is the most deadly snake on earth,now we wonder how this snake

has excelled all the other species well it is simple it feed on deadly rodents like rats which may cause serious damage or kill a snake,no other specie of snake feeds on such deadly prey item,So with this we can conclude that snakes feeding on larger & dangerous prey has more toxic venom than a snake which feeds on smaller prey.how ever there are even fossils which reveal that a snake by name Pachyrhachis has 2 hind limbs,which mostly use to live in water which was around 5 feet in length.

(an artistic image of Pachyrhachis )

(fossilised iamge of Pachyrhachis )

The other convincing evolution theory is that lizards had the venom glands which are even seen in modern lizards like gila monster,Mexican beaded lizards.It was found that large komodo dragons has a vestigial venom gland,As komodo dragons are bigger reptiles the venom glands had no use,how ever scientists still did not knew how venom glands became a vestigial part & instead of that it was replace by bacterial saliva which consist of 80 species of deadly once which also act as venom.

It is being proved that around 1200 species of lizards had their saliva almost like venom an experiment was conducted in which saliva of lizards was collected in a beaker & a soft tissue is placed in it,Amazingly after some time the tissue present in the beaker was completely digested,you venom is one such thing which digests the prey inside out.So we can conclude that most of the lizards have not really lost their venom

Now snakes which kill their prey by constriction they need a bulldog grip on to their prey & to grab hold ,as course of time they have evolved 100 backwards teeth & muscles which definitely kills a prey by constriction.So the primary things are backward teeth & muscles which replace venom.

So we have studied about the venom which is nothing but modified saliva produced in the venom glands which has concentration of proteins as a part of over studies we have learnt that venom has evolved in lizards but developed in snakes,there is one thing we need to stress on why is the venom of Inland Taipan the most venomous when compared to less venomous colubrids? Even this is an evolutionary aspect we need to note,in case of Inland taipan that feeds on the plague rat which is one of the deadliest rodent & is able to kill considerable amount of small snakes so if Inland Taipan has to hunt that kind of dangerous prey it needs to have more potent venom,the venom is so potent that it will kill 500,000 mice now that is too much of them when compared to other snakes which hunt a normal prey which is defenseless.

In case of colubrids which hunt small prey like lizards which don't need extra set of skills & more potent venom.

The same evolution is applied to anacondas which hunt prey just as the size of small animals,so they need more muscle in order to take down larger prey like the capybara & some times they even take down medium sized caimans.This is a part if evolution.

There are some wonders in the reptile world one like that is the resistance to the hemo toxin seen in the king snake even this is a part of evolution,if king snake would not have lived in place where rattle snakes lived might be king snakes would not get resistant to the venom.

The other theories include use & dis-use theory which was proposed by the Lamarck according to it there where burrowing lizards which have emerged as the early lizards

sense organs:

People wonder why the snakes stick its tongue out often,the main reason is for the smell.The sensitive forked tongue collects the scent molecules from the air and the retreats back into the mouth and the scent molecules enter into small slight of jacobsons's organ which identifies the scent and send signal to the brain through a small nerve about concern specie.Their eye sight is good but not as good as cats

(the animated picture of a copper head snake of north america)

They have noses in additional to that some vipers & pythons have a pair of heat sensing pits along with a pair of nose.Through these pits a snake can see the world in infrared image,snakes with this pits can even hunt down the prey even at nights cause most of the vipers are nocturnal,a snake can perfectly strike a prey even when eyes closed.The yellow region of the mouse shows that it's blood is worm & the speed of blood circulation is very high,so if a snake wants to strike a mouse always it strikes at the center,higher the speed of blood circulation the quicker the prey dies.In additional to that a snake sticking it's head on the ground can even sense small vibration of the coming prey or predator,through a bone called pterygoid which is present on the lower jaw,these replace their ears.The eyes of vipers are vertical that means they are nocturnal and most of the elapids(cobra family) have a completely round eyes this shows that they are diurnal snakes.

HOW DO THEY LIVE

Snakes have found amazing way to adapt like no other animal.Basically snake are poikilothermic that means they are cold blooded creatures they need to change their body temperature by socking heat from sun,most of the time snake are found on rocks & on roads due to this reason.As the snake gets warm up it will become more active & agile than what it is before.The more the snakes gets warmed the better & the accurate the strike will be it is not uncommon in reptiles.some snakes go extreme like desert horned adder which can survive the hot desert & thrives,the european adder can survive in the arctic circle & perfectly adapted to such environment.snakes can blend into the nature,their body structure also changes according to their habit & habitat for example a tree snake is always slender it's body perfectly adapted,rain forest snakes are stout & heavily builded they wait for the prey to come by themselves while being in the camouflage,all colubrids have slender body,while all the boidaes have very stout body & kill their prey by constriction.The followingare the snake which are camouflage in their natural habitat .

Snakes are ultimate animals in camouflage if you can see the above picture its a desert adder which is almost invisible,the picture above that is the eastern brown snake which is the total definition of the camouflage.This is the hunting mode of the snake.Some water snakes have also adapted to live in water which are classified under the group hydrophidaes,a sea snake can live under water for more than 1-2 hours for hunting down the prey,few snakes like mangrove snakes have adapted to live in mangroves there are few snakes which can glide .

1.MECHANISM OF FLYING SNAKES.(how to they live)

part one in how do they live

(ornate flying snake during the motion making it's ventral surface flat)

These snakes come under family chrysopelea .The flying snakes are really amazing to see,they have unique designs on their skin.The flying snakes fly to prevent predators like eagles,hawks & other bird of preys.First it will select a long tree & climb till the canopy.from there it will reach a branch which could sustain it's body weight.it takes an 'S' shape leap of the branch like the picture beside.after the leap the snake compresses it's body & forms large flat surface on the ventral region,just like sky dives do,this is effective & snakes can travel long distances like 500-800 meters.The snake assumes 'S' shape so that it can take a sudden left or right turn.this is simple but it is sophisticated mechanism during the landing the snake losses it's 'S' shape & will not get hurt.This took millions of years for evolution.they often live on forests as they are found in the rain forests of south east Asia places like India,south china,not only snakes but also few lizards have also evolved to glide through the air.these snakes feed up on the bats,lizards.small birds & even frogs.they are 5 species

2.SPITTING OF VENOM

(Mozambique spitting cobra)

The evolution of snakes have lead some snakes to spit venom these are consider to be highly evolved.It is too sophisticated mechanism these snakes are called as spitting cobras,it is a bizarre fact that only few cobras fangs are build for spitting venom up to 8-10 feet accurately.there are totally 9-10 species of spitting cobra in the world they are found in Indonesia & Africa it includes species like south Indonesian spitting cobra,black necked spitting cobra,Mozambique spitting cobra,Rinkhals spitting cobra & etc.the reason why a cobra can spit is hidden in it's fangs generally all snakes have small hole at the bottom of the fang canal,but the spitting cobra has the hole at the center of the fang through which the venom comes out we need to study this comparatively.now the fang on the left is an ordinary snakes on the right side is the fang of spitting cobra,as you can see the difference the left fang has large opening & the right fang has small opening giving the snake some time

Mechanism is really amazing the snake first inhales air making it's chest as large as possible,there is small hole like pistol near the mouth called as glottis it is a special tube structure which allows the snake to breath while feeding on to the big preys like a calf,through that glottis it exhales the air just like a high pressure tube allowing the gas to come out & then it compresses it's mussel allowing the venom to flow though the fang & then it come out of the hole the exhaled air allows the venom to travel long distances,this procedure is completed in fraction of seconds.The snake on the left is a zebra spitting cobra showing it's glottis(the black hole).Most of the spitting cobras live in the rocky region & Savannah region.if the snakes venom gets in to your eyes you need to cleans it immediately with water or else you will go blind.This can be prevented by using a simple transparent face mask,most of the herpetologists use it while doing research.These cobras may grow up to 7-10 feet in length.they move their head along with the prey eyes.

HOW DO SNAKES FEED

(a cave python hanging upside down to catch the prey)

The feeding mechanism is really intrusting as they are capable of eating prey larger than it's head.All snakes are carnivorus that means they only eat flesh.Most of the people wonder,how can a snake eat such large prey?it's simple it has elastic ligaments around it's mouth while humans on the other hand have elastic ligaments too but in limit.It seems that snakes have crossed their limit,this allows it to eat larger prey.it's not just because of the ligaments but the snakes's upper jaw & lower jaw are connected by a small bone called as quadrate which allows the snake to attach & detach it's jaws.this is how it works before feeding on to the prey it gapes it's mouth to detach it's jaws & after feeding it gapes again to ensue that the it's jaws are reattached.A snake can survive in the extreme places where food is scarse one such place is desert.The desert snakes have found amazing way to capture their prey most of the desert snakes skin pattern will blend with the sand,a desert snakes venom so effective that it will kill it's prey almost instantly.Most of the snakes diet on lizards,frogs,birds,molluscs,bats,sometime snakes.The snakes diet also depends on the place it it living for example a snake which lives in the water lagoons like a Checkered keel back snake will feed on small lizards,frogs but it does not feed on the molluscs or bats,a cave snake like children's python or the small vipers will feed on the bats or small animals but it does not feed on other snakes it goes on like that.A snake's digestive juice is 5 times better than human being allowing the snake to digest even hard things like horns & bones the snake will consume the prey head first then the entire body.snakes like boas constrict it's prey & suffacates the prey while on the other hand venomous snake will kill it's prey by injecting venom into the blood stream.some snakes like reticulated python are capable of eating even human being.if a snake eats a bird or a mouse it will have to rest for 1-2 days depending upon the size but it a large snake like anaconda eats a capibara or a caiman it will have to rest for 4-5 weeks or even more.A snake like reticulated python if eats a cow or medium sized animal it will have to rest for an year or so.a python & anaconda has 100 teeth arranged in 4 rows 2 upper & 2 lower.some stout snakes like gaboon viper lurks in the nature it will camouflaged while hunting the prey.

(a mole snake regurgitating a frog)

After feeding every snake rests,it has the unique ability to regurgitate the food.It will often do it while threatened as the snake has to move quicker.it does it by contracting & relaxing the neck mussels.by this way it can escape from the predators faster

(an African black mamba opening it's mouth)

some snakes like the African black mamba relies on it's agility.it is the fastest snake in the world a mamba can even strike you on your face it can lift it's 2/3s of the body in air & capable of going at a full speed of 21kmph.it' called black mamba cause it's innner lining of the mouth is black not because it is black

There is another reason why snakes can go starving for more duration after consuming a large prey,this is something related to its small intestine,it has many small minute hair like structure called villi,These are mailny used for absorbtion of nutrients from the digest prey even we have it.But in a research it was proved that the snakes on eating will have relatively longer villi to absorb most of the nutrients unlike the microvilli present in starving snakes have are smaller in length this is self mechanised like the biological clock. Through this mechanism they can go starving for months or even years.

DEFENSE MECHANISM OF SNAKE

The snakes can defend themselves when threatened,they bite you it's not the mistake of snake but it is our mistake we venture each & every place even hideouts the result a snake biting you for no good reason.The main weapon of defense is the VENOM snakes have evolved it since the time of the dinosaurs it took millions of years to develop venom it's not like single use they have special glands called as venom glands,it is a sac like structure where venom in produced & stored.the venom of the rattle snake is 100 times stronger than cyanide.venom is complex & concentrated mixture of proteins so a snake can't wast it for cheap.sometimes snakes give a dry bite i.e a snake bites but it does not deliver venom then the person seems to be lucky especially if its the venomous snake in the world.King cobra has the largest venom sacs producing 2 table spoons of venom.

Besides venom some snakes have special structure which they show on threatened.This the simple way to avoid predation & the snakes do not get hurt,snakes like cobras open their hoods by expanding their neck muscle showing off a bright & clear message that it is near by & dare don't touch me.

(cobra snake opening it's hood tell us the presence)

(an eastern diamond back rattle snake taking the shape before strike)

Rattle snakes during the course of time evolved rattle which is considered to be modified scales.Every time the snake sheds the skin it is added up with a new rattle at the posterior region.it will shake it's tail & produces the famous rattling sound this also serves as the same purpose preventing predation.Most the desert viper do have rough scales called as keel scales.snakes like saw scaled viper produce a unique sound by rubbing it's keel scales it sounds like a rattle snakes's rattle.snakes like king cobra & russell's viper hiss when threatened sounds just like steam of cooker.in united states itself snakes kill about 1000-2000 people a year,people who go to deserts often get bite by sidewainding adders or desert coral snakes,as they are too far from a city or a town for medication they will inevitably die.

VENOM(INTRO)

snake slowly started to evolve yellow juicy venom.scientists called it as snake saliva.snakes venom can be of different forms like a cobra has neurotoxin venom which will affect the internal organs like nervous system disabling the flow of blood eventually the whole body will shut down,vipers have hemotoxin venom that which is capable of destroying tissues .the result is worst the part should be amputated based up on the conditions,another kind of venom is cytotoxin venom which is capable of destroying skin around the bitten region .all 3 kinds are venom has adverse effect on human beings.venom causes a rat to pee so that the snake would slither through the sent trail to catch the dead prey.

venom is measured in the units called LD50 which means lethal dose 50,other units LC meaning lethal concentration & LCT(lethal concentration & time).the toxicity of snake's venom is judged by these.snake venom is complex mixture of peptide proteins which is produced slowly.if a snake is milked completely it will regenerate it's venom with in 2-3 weeks or below depending on the food it eats,about millions of years a go when snakes started to thrive on land they are often eaten by the dinosaurs they do not have any weapon of defense this forced the snake to evolve venom.glands & produce venom.but few snake like boas which could not make up with venom but they brought their brude power into the action cause boas,pythons,anacondas did not evolve venom

(bit from a cobra is complete annihilation,the boilings are the symptom of the bite as you can see some part above the ankel is rotten)

(a poor 15 year old boy was bitten by dangerous snake in south america the fer de lance pit viper now the child left leg should be completely amputated it just the matter of hours that costed him a limb)

ANTI VENOM

If a person is bitten by a snake he is rushed to hospital to serve him some anti venom.the anti venom is nothing but antigens which will break down the venom molecules.Anti venom can be produced when the venom of concern specie is injected into a horse or cattle,after this statement many people would be wondering why will the horse not die,it is simple they are resisted to the venom.when it is injected horse will produce antigens or antibodies,these antigens are taken out by the injection

(mongoose attacking a cobra)

(a honey badger attacking cobra with out fear)

some animals like a mongoose are capable of killing even a cobra it is because it is resistant to snake's venom not all but cobra besides the reflexes of mongoose are twice as faster as cobras,some animals like honey badger are capable of killing & eating a cobra this has also got the snake reason,that animal is resistant to cobra venom.just like snake evolved venom these animals have as got resisted for venom

if a person is bitten by a snake but after reaching the hospital if the person does not find the anti venom of concern specie then the victim is given a local dose which will buy some time until the anti venom arrives.few places in Africa don't even have anti venom of black mamba,which is the deadliest snake of Africa.

FUN TIP:

a tapir eats lots of leaves in one day including poisonous once,but at the night it eats clay as clay dissociate poison molecules.

some monkey eat even poisonous fruits & even leaves in the day time to dissociate the poison molecules they eat char coal.

TIPS AFTER YOU ARE BITTEN BY A SNAKE

the following are the instruction to be followed when your are away from help or hospital

call 911
firstly do not panic as you get panic your heart beat raises as it beat fast the blood circulation speeds up allowing to reach the venom to the heart & so the death
after bitten you need to use very tight band & should be placed behind the wound so that the blood circulation will be very slow,if the victim needs support place a stick wrap with the band along with it.
meanwhile if you have friends or colligue tell them to suck out the blood containing the venom molecules note:Since it's venom it can't kill you if u drink it,it will be only effective when it is injected into the blood steam,so if a person accidentally drinks venom while aid he is safe.
this should be done until the an ambulance arrives to take victim to hospital.after going to the hospital you should be able to tell about the bite of concern specie or else they will give you a local dosage.
the simple way to tell weather you are bitten by a poisonous snake or non poisonous snake,when a poisonous snake bites a person it will leave 2 dots while a non poisonous snake leaves 4 dots
to be at the safe side go to the hospital some snakes do give a dry bite even though they are poisonous that means a snake will bite,but does not inject venom.
symptoms of the bit varies from snake to snake in most cases but common symptoms are nosia,metalic taste in the mouth,kind of giddness,breath lessness,vomitings are some in common.
the basic identification of snake weather a snake is poisonous see on it's head if it is triangular it is definitely a poisonous viper,if you take a keen look on the snake's face if you find 2 pits other than nostrils then they are definitely a poisonous snake,the depression between eye & nostrils is a look of poisonous snake.
most of the cases if a slender snake bites you you are free from danger as they are colubrids but few of them can give a fatal bite like boomslang of a Africa.

ANATOMY OF SNAKE

since it's a slender body the anatomy of snake is sophisticated.all the internal organ are compressed like a tube.when a snake eats a prey it will enter into the stomach through treachia, pharynx,oesophagus.this is an intricate picture of a snake showing off different parts of the body to protect this organs there are 150-200 ribs may go up to 600-700 in case of pythons.the heart of the snake is relatively small when compared to the body.when prey reaches stomach it is totally digested by digestive enzyme & nutrients are absorbed in small intestine,nothing is remained.At the posterior region there is sperm duct which will release the sperm for reproduction.the organs of snake are similar to that of human beings ,as you can see the picture the stomach of the snake is bigger,as it should digest bigger prey as there are no limbs the heart will preserve the energy for pumping blood,but a lot of blood should be pupped to the vital organs.

REPRODUCTION OF SNAKES

most of the people around the world think that snakes only reproduce by laying eggs thinking that they are only ovoviviparous but the entire family of viper produce by giving birth to young once.vivo=i live,perae=i give birth,this is take from latin word.even boas & anacondas give birth to living once.the breeding season differ from snake to snake of course snakes sharing same environment will have same seasons for breeding a snake can produce 10-20 eggs at a time or even more in some cases.they guard their eggs till they hatch & most of the snakes leave their newly born child to grow by themselves however some snakes will guard their eggs up to 2or 3 weeks like a bamboo pit viper.A female filled with eggs has an enlarged belly so we can easily identify weather it is pregnant or not.

While king cobra is the only snake which will built a nest & guard it's eggs.breeding in snakes is spectular to watch the male & the female will coil their body like spring to each other,there will be high chances of breeding this looks like a spectacular dance.there will be wars between a male & an another male for breeding as there are 2 mails who want to copulate with 1 female usually the war leaves off wounds but in some cases even death.

In this process the male will slowly rub his spur to females sac which will stimulate eggs in the stomach leaving of beautiful eggs after this they find a secure place to lay eggs where there is no danger but when a man passes by that region will be strike to the death by male,male in most group of animals are highly territorial & aggressive,they do any thing to bring down to their knees.

(a very big female anaconda is surrounded by many male anacondas)

While in some snakes like boas,pythons & anacondas females are bigger than males in that situation a female is capable of mating with several male snakes at a time.this is absolutely scenic view.all the males copulates while female being at the center this looks like a a giant ball & so it is called as breeding ball.the females are twice as large as males.most of the anacondas copulate while being in the swamp itself.

Just like the above the picture with several anacondas around a female snake.this process may take may horse & the female is payed of with beautiful little children & gives birth directly to young once laying about 20-30 babies from that moment they are left alone & so only 4-5 babies may make out to adulthood

In sea snakes copulation occurs in the water itself but the female lays eggs in an air pocket which means the eggs are safe from the water.above that all ovivipary snake produce leathery shells which means it is water resistant,as sea snake lay eggs in air pocket they are safe & warm soon the baby sea snakes hatch from the egg,but the main threat has just begun as a female lays 20-30 eggs only 4-5 may proceed to adult hood & the reason is small animals like seals may eat the eggs before they hatch or they may become prey after reaching adolescents age.

(a group of garter snakes seem to produce like worms)

The life span of snake is less like 10-12 years max but few snakes like anaconda may live up to 60-70 years,but short life snap snakes get faster sexual maturity.the gestation period may very from snake to snake .how ever there is a record breaking snake which produce about 100-120 babies at a time & it's called the garter snake.the picture on the left is a group of garter snakes.all these snakes are produced from a single mother & a single father.

CLASSIFICATION OF SNAKES BASED ON FANG STRUCTURE

Scientists classified snakes based up on there fangs as it is an easy way to differentiate snakes.there are four types of fangs among snakes.now even you can different a snake by knowing this.

1.AGLYPHOUS

This type of fangs are seen in large snakes like boas,pythons,anacondas.There are 4 rows of fangs with 2 rows on the bottom & 2 rows o the top.there are about 70-100 backwards pointed fangs giving a vice grip if a hand goes between the jaws it will never come back unless the snakes jaws are opened 180 degree.this kind of jaws feed on prey like birds, deer, calf etc it will include the diet of boidaes.aglyphous kind of jaws need heavy mussels to control the jaws & flesh tearing bite.

2.OPISTHOGLYPHOUS

This is seen in the family colubridae this is also called as rare fanged snakes,they have their fangs located backwards so it is difficult for a colubrid to strike human beings,but there is a colubrid which can kill us it is called as boom slang snake of Africa.with these jaws a snake can feed on lizards, mouse,frogs etc.as you can see in this picture all the fangs are located backwards the snake will be using only one pair of fangs & the rest are upcoming once,there should be quick replacement in fangs as fangs are half of snakes property.

3.PROTEROGLYPHOUS

This like of jaw structure is seen in elapidae=cobra family.this also consist of 2 rows of jaws on the lower side but they are only useful while feeding not for striking.the upper pair of jaws are fixed they are not movable,hence there will be no difficult in striking as the fangs are in position.the posterior part of the fang takes a U curve,as you can see the fang is bent like a nail.the venom of these fangs is neurotoxin killing the prey by shutting down the heart.

4.SOLENOGLYPHOUS

These are the fangs of the viper.which act as switch blade they have movable fangs.these fangs are protected in the mouth by a layer of mussel sheath which will keep the snake's fangs protected,during the strike fangs come out this sheath & penetrate into the flesh,this is advanced type of fangs only seen in the family viperidae.they open their mouth almost 170-180 degree to ensure that the bite is full effective with sufficient venom delivered.the venom used by this fangs are hemotoxin venom,which destroys the blood tissues & with excruciating pain.

CLASSIFICATION OF SNAKES BASED ON LOCOMOTION

There are three types of locomotion in snakes which also is an easy way to determine difference between the snakes.they are concentric locomotion,sidewinding locomotion,rectilinear locomotion,okay lets have a brief look about them

1.SERPENTINE LOCOMOTION

The serpentine locomotion is the most common type of locomotion,where a snakes slithers taking an 'S' shape.

as you cam see in the picture the body of the snake bends at the middle & the rest of the part will follow the same.this is seen in all kind of snakes irrespective of the family of snakes.this kind of locomotion is not seen in stout & larges snakes like bidaes.this is not seen in the desert snakes like sidewinders .

2.CONCENTRIC LOCOMOTION

this is a worm like movement where a snake pulls it's body,it uses it's front part of the body like an anchor & pulls the rest of the body in the same straight line.This is seen in the small snakes & colubrids .

SIDE WINDING LOCOMOTION

(a side winder moving with full speed to escape the scorching heat of sun)

This is really intresting,this is an adaption of the snake in desert.this kind of locomotion is a very unique way to escape the scorching heat of desert floor.through this locomotion snake only touches the ground at 2 points,though it seems as the whole ventral surface of snake touches the ground.the side winding snakes are fastest moving animals of deserts.they leave of great geometric designs as they pass through the area.now even you can tell weather a side winder live in deserts by looking at their trails.

If a side winder is place on the marbled floor it will move in the serpentine locomotion.it is just a desert adaption.there are 3 species of side winders a)sonoran side winder b)colorado side winder c)mojave side wander.

RECTILINEAR LOCOMOTION

(an Indian rock python struggling to move on land)

This kind of locomotion is seen in heavy builded snakes like boas & pythons.This is the process by the which the snake travel forward by contracting & relaxing the muscles as boas,pythons & anacondas are builded with muscles.Rectilinear locomotion in relatively a very slow locomotion when compared to others that is the reason why most of the boas & anacondas spend there time in water as they are twice as faster than on the land.usually they come to the ground for resting & digesting the food.So when a snake this threatened it will regret it's food allowing it to escape with more velocity.

Black mamba is the fastest moving snake around 20 kmph that is very fast for a 12 feet snake which can lift it's half of the body & can still move will full throttle.

LIZARDS

The amazing thing about lizards is that they have excelled even most diversified snakes & occupying all place on earth except Antarctica.These are slender little creatures which occupy very less space & very well adaptable when compared to snakes,so they have became successful reptiles.There are about 5400-6500 species of lizards on this earth.Geckos & some species of skinks have ability of autotomy which means they shead they tails in order to escape from predators,Their way of commenucations ig generally gestures or by pheremon which is by smell.These reptiles are very brightly coloured from brown to green,blue & even red colours.

GENERAL ANATOMY
They may range from 1inch to 10 feet in length & the weight ranges from 2-4 grams to 175 kgs.The body is divided into head,abdomin & tail,all lizards have their tails larger when compared to head & abdomin.Lizards mostly store fats in their tails,but some groups of lizards loose their tails very oftenly to escape from predators.The exoskeleton consists of scales which are sometimes keeled(rough) in some species & a fine leathery texture in some lizards in most cases scales are overlapping.The endo skeleton consist of small bones,Lizards have extremely flexible spinalcord which they use it for rapid movements & going through the burrow which is almost the diameter of the lizards itself.All lizards bask under hot son to increase their body temperature as they are cold blooded.Studies have proved that U.V rays energize lizards more than any other light.All lizards are oviparus except Yellow spotted night tropical lizards which give birth to living once.

Now we are going to study about the types of lizards.

agamid
chameleon
skink
anole
geckos
veranus(monitor lizards)
iguana
heloderma(gila monster & mexicon beaded lizards)
Horned lizards

AGAMID

Agamids are the most diversified lizards in the world,there are over 350 species of agamids.These are distributed like no other lizard on this earth.Most of the agamids have dry & very little over lapped scales,these are relatively smaller when compared to chameleons but larger than geckos.These are classified under the familiy agamidae the great thing about them is that very few lizards of this group will shead their tails.

How ever there are some fan like projections on their throat this is a pecular feature in fan throated lizards,they display their fans throats in order to look bigger.Agamids live in forest region,in deserts,in grass lands & some time even in houses.

They come in different colours like bronze coloured,black brown,pale coloure though they may vary in their dorsal colours they don't vary on their colours,almost all agamids are coloured pale or plae yellow on their ventral side.Agamids are the only group of small lizards which use their forked tongue for finding prey.

They are succesful predators as they are even found in hot deserts like the zebra tailed lizerds & very cool place like mount everests like the kashmir rock agamia which lives in almost -10-20 degrees centigrade.

They mostly live on land very few live on trees,they have movable eye balls which always lock on to their prey,most of the agamids are insectoverous they feed on insects The life span may range from 1-6years.

There is sexual dimorphism in few species of agamids like the peninsular rock agamid in which males have red neck & females are completely brown.There are some amazing species like the basilisk lizards which walks on the water.

They actually do this by placing their foot on the water for fraction of seconds which cause an air pocket & this forms a land on water that means it literally can walk on the water,it is reported that these lizards are capable of crossing river banks.There are over 6 species of basilisk & the plumed basilisk.

It has got some unique species like the Horned lizard,Thorny devil,draco(flying lizards).
A horned lizard if found in american desert & is capable of shooting blood from their eyes by 2 feet.They do it by increasing their blood pressure near their eyes which will burst open their vein near eyes,They do it so to escape from predators as blood has fowl smell.

Thorny devil or lizards are very unique species which are foungd in the desert of Austalia.Their body is completely midified to tha harsh enverinment thay have thorny projections on their body hence their name,they feed on ants & termites,& feet at the rate of 120-200 per minute hence the name devil.The most amazing feature about them is that they do not drink water directly with their mouth they have hydroscopic skin,which allows the water to pass through it and finally into the mouth.

The flying lizards or dracos are rare lizards with the power of gliding from tree tops.They are able to do this by an unique feature which is not present in any reptile.They have overlapped sclaes on their belly or abdomin region,after reaching a tree top they glide from taller tree to shorter tree during this peroid they open their overlapping scales just like a sky diver.They do this primarly to escape from predators.

At the end of each digit there are 5 well developed claws which give a ferm grip over the substrate allowing them to move quickly & rapidly,Few agamids have small crusts on their back inst ed of overlapping scales.

DRACO(FLYING AGAMID)

These lizards are called the flying lizards, which are classified under the family agamidae they are found in the rain forests present in south east asia.There excoskeleton consist of smooth scales along with over lapped scales near the abdomin region.These are around 20 -30cm long or less than that.

Their flying mechanism is very intresting in order to escape from predators or to cover long distences.They open their over lapped scales on their abdomin region this is nothing but the extension of the ribs,you can see the margins on the over lapped scales,Since they live in long tress First they climb up the long tree which allows they to cover atleat a distance of 100-200 meters & when the lizard spots a predator i.e bird of prey thakes a leep off an extended branch then opens it's over lapped sclaes allowing the air current a huge surface area just like sky divers,intresting thing is that it can change the directions in mid air which is done my the most essential part called tail.The tail will give it stability as well as a switch gare in turning directions.

Female lizards only come to ground during laying their eggs they do it by making a hole in the soil sice it is a rain forest its soil is very soft,she makes hole by driving her head into the soil & lays eggs around 3-6 at a time.

CHAMELEON

Chameleons are one of the most spectacular living reptiles with an unique ability to change their colours.Every chameleon in this world has a prehensile tail which they use it for graping to the branches.All most all of them are tree dwelling very few are land dwelling creatures.Their size range from an inch or less to 35cm which is the largest chameleon called the parson's chameleon.

Chameleon change their colour very oftenly they do it so because they have 3 different skin layers just like epidermis,mesodermis & endodermis in mammals.

FIRST LAYER:xanthophore & erythrophore which has pigments like yellow & red.

SECOND LAYER:iridophore & guanophore which has pigments like blue & white colour.

THIRD LAYER:It is temperature dependent as it consist of dark pigments called melanin.

As you can see even chameleons use all 4 primary colours to bring out secondary colours.

This mechanism works when light falls on the chameleon's body it get penetrated into the body & gets reflected back during this time a chameleon is capable of expressing any one colour of a single layer,For instance if you see s blue chameleon with few yellow or red stripes it has expressed it's blue colour of it's 2 layer,so you can find a chameleon in different colours.

The colour doesn't always depend on the environment sometimes the even change their colours with respect to social behaviour,emotions an angry chameleon is always black in colour,Some desert dwelling chameleons have their body coloured partially white & black they do it so because back colour absorb more radiations & white colour radiates the light thus keeping the chameleons body cool.

Most of the chameleons are insectivorous,they are very famous for their long tongues ,a chameleon's tongue is 6 times longer than its body length,it has a bulged sticky end on it's tondue which will make sure that it's prey can't escape from the tongue hold they can do this in less than 30 thousandths of a secondwhich is more quicker than blink of an eye.They have sharp teeth attched to strong jaws,thsy aare monodent which means they do not have different knids of teeth,a chameleon only has a single row of iscers on the lower jaw & upper jaw.

Their body is completly designed for forest living,they have syndactylus legs which they use it for grabing branches,The diameter of branches perfectly fit into chameleons arms.,They are very slow & calm species,their metabolic rate is very less when compared to mammals,as sead above chameleons have very unique tail which is only seen in some monkeys

A CHAMELEON CAN NOT RELEASE OR REGROW IT'S TAIL,Their excoskeleton consist of smooth scales with modified crusts on their back, & endoskeleton consist of smooth & sofet bones which are not cartilagenus,chamleleons don't drink water because water produced during their metabolism is enough for their body proportions.How ever desert dwelling chameleons have keeled scales to prevent the water loss through skin.

Chameleons exhibit sexual dimorphism, males are bigger than females & females express their emotions more than males & this can be noted by their colour changing ability.Some chameleons rarly get a chance for mating it's not beacuse of males lossing thier fight inseat it's population,a male rarly meats female in his journy,he & she knows that it is very prestegious event,while some die with out mating generally this condition is seen in harsh enveronment like deserts.

Chameleons have very good vesion when comapred with their smaller quesins,they have compund eyes which move indipendently the main advantage about their eyes is that they are protruded out & so their eyes are capable of catching even dust in a nail.Chameleons are the only reptiles which can see their world 360 degree they are completly aware about hovering hawks & eagle which mainly feed on chameleons.

A chameleonis are solitary reptiles which are shy & extremely non social.Openning their mouth wide & hissing is a sign of angry chameleon one which you don't want to mess with.Some chameleon species which have horns on their heads like the lackon's chameleon fight their same gender species with their horns.

SKINK

There are about 1200 species of skinks,they come in wide verity of colours,they are clasified under the family scincidae,they roughly loom like lizards they have reduced legs with a stout body,some genera are without legs like typhlosaurs they have a slender body without legs amost like a snake.There size range from few cm to 1 feet which is the largest skink called salmon island skink.

Skinks naturally prefer burrows which gives them shade during hot sun,In spite of having reduced legs or short once they are agile species.The exoskeleton consist smooth & shining scales which reflect most of the radiations of sun.They come in different colours like black,brown .The larger species of skink are called maybua.

Skinks are insectvorus reptiles,their main dite includes crickets, grasshoppers ect..Skinks have eyelids to protect them from dust.The skinks which are grown in the houses their main dite incudes leaves,frutes & vegitables.

These lizards have may predators like hawks howring in sky,racoon,cats,dogs etc.Skink are oviparus that means they lay eggs around 6-10 which will soon hatch.

ANOLES

Anoles are less diversified when compared to agamid,there are roughly about 300-400species of anoles, clssified under the subfamily polychrotidae.There are about 11 genera out of which only 4 are concerned.These are just like geckos they are fast moving ,slender body,Lims are almost the same so a fast moving anole can be mistaken as a gecko these are only found in america..

There are only found in america parts like southwest united states, in caribbean etc. they exhibit sexual dimporhism like the green anole males are green in colour while the females are brown in colour. Some species have dew laps which protrude out from their neck which looks like fan this is made up of cartilagenus bones,During breeding season males open their fans to attract female.

Anoles are terrristrail species which exhibit some actions like push ups which resemble it's area,Their exoskeleton sonsist of smoothe scales which do not have overlappings .

Even these lizards are oviparus layer around 5-10 eggs.

GECKOS

These are sectacular reptiles but these are small groing about 5-65cm like the Delcourt's Giant Gecko . These are distributed arcoss asia,africa,.since they are small they are very well adapted to the human civelization or the house envirement,most of the gecko we find in ourhouses are little bit smaller than others & called the house geckos.these are classified under the family geckkonoid .they come different colours from yellow, golden ,green, brown etc.The greates thing about geckos is that they even clinm vertical walls with ease & can very climb as slippary as glass,this is due to their pads which are present on it's foot.

If we take a close & microscopic look you will be finding setae or chetae which are long hair like structures which are again divided into branches, there are about 1-2 million of these in each paw.Each setae has a length of 50microns, at the end of each paw there are clows to give it more grip on land, the setae machanism od adhesion is so universaly accepted that people even started their air sucking pads to clean glasses of tall buildings.

Intermolecular forces are exerted by the molecules on each other & affect microscopic properties of the material of which molecules are apart.There are some weak van der waalas forces between the setae & the wall allowing the gecko to climb with ease.

So a gecko can even move very swiftly on the vertical walls,These setae are arranged in bundles of fibers.

MONITOR LIZARD

These are the largest lizards of most of the kind,the largest one is komodo dragon which can grow up to 10 feet in length followed by crocodile monitor which grows around 8 feet in length.These are found in africa ,asia,australia.there are about 55 species which are classified under the family veranidae. They come in few colours like brown,black with yellow spots.Since they are very large their first line of defence is their tail which is larger than it's body one flick can crack bones.

There exoskeleton consist of rough keeled scales or some times smooth.These lizards have developed osteoderms which means they have boney plates on their body this give extra protection to monitor lizards,their endoskeleton consist of hard bones of any lizard group.There ventral surface which is called the sternum is soft without osteoderms,so a monitor lizards ventral surface it's weak point.

These live in grasslands,deserts, even live in human civilized area like the veranus komodo (komodo dragon) & bengal monitor & in deserts like the perenti monitor lizard etc.These lizards have very good sence organ when compared to other group of lizards.Fliking of their forked tongue will collect the scent molecues present in the air & sends it back to the jacobson's organ just snakes (refer sence organs of snakes) this is sence of smell.

It is proved that monitor lizards have best sence of smell of any group of lizards,they can even smell a dead carracas from 5 km.They do not have very good eye sight to they need to rely completely on the smell.

A komodo dragons second best way of attacking is a bit which contains around 80 species of bacteria which are very deadly.A bite from a monitor lizard will kill it's prey with in 15-20 hours by blood poisoning just like venom of snake.A part from that komodo dragons have vestigial pair of venom glands which was devoloped in the earlier evolution of lizard to snake,as time passed these venom glands became vestigial which are present in the lower jaw,this experement was conducted by Dr.Bryan Fry

Monitor lizards have largest claws of any lizard group which can grow up to 4-5 inches in length,a blow from it's claws can rip preys flesh into peaces.

The greatest thing about komodo dragons is that a female can fretilize eggs without sperms that is if there is no mate available, & males have 2 penises to mate. A komodo dragon feeds suffeciently & leaves 15% of it's prey behind which are intestines,skeletons etc..

A monitor lizard can even digest horn, hooves & even bones which are made by high calcium by the process call calsification.

IGUANA

They are marvelus animals which are videly accapted as pets than most of the lizards.they are classified under the family iguanaidae.These are tropical lizards which lives in mexico, & central america,these are herbeverous reptiles which mostly feed on grass.There are 2 species included in this family they are the most famous of all is the green iguana which is green & has crests & spines on it's back.These are big lizards with growing up to 3-4 feet in length which majorly includes a long tail & the Lesser Antillean Iguana,this perticular species are endangered.

They have overlapping scales on their body mostly on their throat which are called as turberculate scales.In addition to that they have third eye which is called the perital eye which is present on the top of their head,scientists believe that is is an evolutionary change in th production of eyes as their main predators are the air born bird of prey they have produced this eye in order to have keen look to the vast sky,this prevents from predation.

These are just like tuataras (sphenodontia) which are the only reptiles of new zealand even this reptile has perital eye.The intresting thing about inuanas is that they have 3 hemipenises.Apart from this there is another iguana called the marine iguana.

These are found in huge groups near seas,They are black in colour & during day time they spend most of the time basking under the hot sun,when they are ready they take a dip in the sea in order to find algae which includes their main diet.

Since they are land dwelling they make burrows & lay eggs like most of the land dwelling reptiles because a mud is good insulator which provides humidity,usually their gestation period is shorter.

Since they are green in colour their main method of avoiding predators are my immobilizing them selfs,giving a still position doing this they blend to their enveronmenent like leaves,twigs etc,but young iguanas are packed with full strength & very good perital eye so they make moves very quickly.

HELODERMA

This class includes only 2 living specimens like the gila monster & the mexicon beaded lizard.These are found in mexico & american deserts like utha,These are the only 2 species of lizards which have venom gland & are venomous but not deadly to humanbeings how ever people prevent it as they are found in the middle of the desert & one nasty bite you are way far from medication.

They have keeled scales as they are found in desert,they can't cost for the water.Generally mexicon beaded lizards are bigger & stouter than gila monsters & both have orange lines or spots merging with black body.They are mostly found under the rocks & bolders during day time in order to escape the predation as well as head of the day.

These lizards have venom glands under their jaws & deliver them by their 30-40 teeth or even have venom on their saliva.They have neurotoxic which will affect the nervous system, makes prey paralize & ultimatly death is for sure.Gila mosters & mexicon beaded lizards are considered the missing links between a non venomous lizard to a venomous snakes.So scientist confidently thought that it was the lizard which was equiped with the venom not the snakes & so the lizards gave rise to snakes.

NON VENOMOUS LIZARD-VENOMOUS LIZARD-LEG LESS LIZARD(GLASS LIZARD)-PACHYRACHIS PROBLEMATICUS-VENOMOUS SNAKE

There main diet included small inscets along will eggs,their fevorate diet is the egg yolk which consist of more proteins for their metabolism,they rarly drink water if present as their body produces water during metabolism this type of water is called as metabolic water,this is an adaptation of most of the desert animals.These look like small monitor lizards just like them these have very stout tail & lost the power of autotomy(lossing their tails) as even this is adaptaion devolupment,lizards found with plenty food like geckos & smoe skins do autotomy or self amputation,but these animals living desert food is very scarce & so they must not loose them as most of the fats essential for body are present in the tail region therefour their tails look stouter.

HORNED LIZARD

These are found in american deserts like the senorun,colorodo etc.these are classified under the family phrynosomatidae which includes western horned lizards.These lizards are very famous in us as pets,& most common reptile in california.These species are distributed in dry enverironments.As the name it has several spines covered on it's body ranging from mm to few inches there are large spines about 4-5 on it's head,when threatned it will bow it's head allowing these spines take that place,so when a predator goes for a catch it will get it's mouth pierced with those spines.

These are small lizards ranging from the lenght of 6-10 inches.Their body scales are little bit thicker to the normal lizard living in forestes as it is a desert adaptation,more thicker is your scales more effecient in preventing water absorbotion.There is a promenent array of small spine of few cms running across their bridge scales (place at which dorsal scales & ventral scales combine).These slightly resemble throny devil even they are evolved for the same environmental condition.

These are oviparus lizards,they guard their eggs from predators by showing themselves bigger than the predator,as in case of horned lizard it will lift it's body off the ground becomes a bit more stouter than before doing so it will avoid predation.If that does not workit has got a remarkable way to throw their blood into predators face cause a fowl smell of blood to spread over predators face eventually the predator retreats.

This mechanism is done by increasing the bloog flow in it's eyes so much that the nerves shatter allowing a ject flow of blood pumped off it's eyes.It can pump the blood up to 7 feet in length.During day time they live under the rocks & feeds on ants & termites.These lizards gave lost the ability of autotomy that might be because of less food as far scientists never knew about that.

TORPIDURIDAE

These are less diverse lizards which are found in south america,from colombo to brazil & argentina.The common name of these lizards are new tropical ground lizards,ground dwelling lizards which make small borrows under the ground,these live in relatively cool conditions.These are group of rare lizards which are oviparous which means they give birth to young once.

They generally give birth to 5-10 baby ground lizards,there is sexual dimorphism among few species like the lava lizards they are so called because they live in lava which is black in colour that which became cool & solid black.There are about 7 genera with around 110 species.All are small lizards & ground dwelling among the 7 genera stenocercus is most diversified with around 61 species among andes mountains.

These are rare group of lizards which are able to give birth to young once along with yellow spotted night tropical lizards,only the tropical lizards like these give birth to young once unlike most of the lizard laying eggs with leathery shells.

LEGLESS LIZARDS

These are lizards without limbs,their usual locomotion is slithering just snakes.They are geographically distributed in Europe,Asia & even America.These lizards may be concluded as missing links between a snake & a lizards this is the first piece of evidence.Even in these lizards legs where not doing much work in their locomotion so their was a prominent reduction is their legs.Some of them have reduced legs but can be seen and in some species the legs are completely lost.

Their exoskeleton consist of smooth scales along with soft bone in the endoskeleton.These lizards are classified under the family pygopodidae,these are some times also refered as anguids it is regional name changes from region to region.It consist of 8 families.The most famous of all the family is the anguidae which consist of glass lizards & slow worms which are found in europe.

They can be easily differentiated from the snakes as they have eye lids,ears with well devoluped tempanum,they don't flick their tongue all these fietures differentiat a legless lizards from a snake.Apart from that snakes do have shorter tails but with a long trunk region but the legless lizards have longer tail relatively shorter trunk.They mamy range from 15-20 inches or more,most of the time present under the scrap of metals or wood & grass.These are moslty brown bronze colour & some dark colours like black stripes on bridge scales.

Their main diet includes worms,small invertibrae & inscets some may even eat snails etc.

Scientists are conducting experiments on these lizards why have they lost their legs which is truly an amazing thing because lizards are supposed to be one of the most agile reptiles but one of those lizards has degenerated it's legs.Most of the desert legless lizards swim in the sand to escape on hot sun of the day time.

CROCODILIA

THIS GROUP INCLUDES:CROCODILES,ALIGATORS,CAIMANS & GHARIAL

There are around 23 species of the crocodiles,with 15 species of crocodiles,2 species of alligators,2-species of the ghavial & 6 of caimans.

INTRODUCTION

Amazing reptiles,some times refered as fossilised living creatures since they have not under gone any evolutionary change & they are the true reptiles which where living from the coenozoic period.Their body is elongated & heavily builded,they are the largest reptiles which can weigh over 600-800kgs.The body is divided into head,abdomen & tail,the tail is very well developed in the crocodiles than any other reptile,these are the only reptiles which show more parental care,reptiles have 2 eye lids & non in case of the snakes but interestingly crocodiles & alligators have a third eye lid called the nictitating membrane,this is a transparent eye lid which allows the crocodile to see crystal clear even in the murky water.This is kind of natural selection only animals that live in that kind of conditions tend to grow an extra part or reduce a part to over come the need.

Apart from this they are highly diversified they are found through out the world from australia to america,except europe & antericitica.Some are very large like the salt water crocodile which can grow upto 25 feet while the others like the african dwarf croc rarly grows to 7 feet in lenght.

Apart from the modern crocodiles there are other prehistoric crocodiles from the jurassic period like the sarcasuchus which is the largest reptile to ever exist which can grow to a massive size of 40 feet in length,heres the comparision between sarcasuchus & the modern saltwater crocodile.We have sarcasuchus(front) & the saltwater crocodile(behind).The fossilised remainings where discovered by paul sereno an american paleontologist.

HABITAT

Crocodiles most important thing is a semi aquatic life style,which spends most of the time under water,they are one of the most experenced swimmers in the reptile world,during summer when the lake is dried they dig deep burrows near by the lake as shown in the picture.We can even find bigger crocodiles resting in these kind of burrows.

All crocodiles & alligators live in water that is a hallmark,the salt water croc lives on the merine water while the american crocodile lives in freah water while the caimans live in the merkywater,according to the lamarkisam the parts which are used very less by the animal there is less developement or non in case of crocodiles legs,they rarly use thei lega under water & crocodiles only come out for basking for the rest it is in water,they will not migerate with their legs that is very rare,so there is less developement of their legs when comapred to their jaws which are highly developed with bone crushing bite.

crocodiles are teritorial animals & can attack animals which enter into their teritory except the hippopotamus,these are massive creatures which can weigh nearly a ton even they are territorial but they even give space for crocodile,hippopotamus lives in water the entire day & come out at night for feeding.But this intraction is seen only by the nile crocodiles of africa.

Basking is the best habbit of the crocodiles they need to bask as they are poikilotherms meaning they are cold blooded they can't regulate their body temperature,in order to regulate they need to absorb sun light & increase their body temperature which is initially around 15-17 degrees centigrade after basking their temperatures increase by 25-26 degrees centigrade,this also helps them to increase they speed,power,eyeslight, & activates the brain & heart stimulating more fresh blood supply to their body parts.So they act as solar panels but less radiators,during basking they open their mouth for the removal of the fleah which is stuck in between their teeth which is done by other little animals called birds,there are few species of birds which eat away the fleah present in between & the crocodiles only allow these birds to enter thei mouth,hence crocodiles are not only making themselves satisfy but alo the birds.

FEEDING HABITS

Crocodiles mouth parts perfectly suits for it's food habits,they usually prey on wildbeest,zebras etc.,they need to have great muscle power in order to take them down,so they take advantage of the water & drain them to the bottom of the lake & after some time the zebra or wildbeeat dies with out oxygen.

This acutally happens when the migeration takes place,migeration is one of the essential habits of animals,eliphants migerate all the way from north africa to sout africa they cover large distances,zebras & wildbeest have to face may herdils to reach the sanctum place filled with trees & grass for that they need to corss many rivers filled with crocodiles this is one easy way for crocodile to feed on it's prey while the other way is learking under water.

Crocodiles can hold their breath for 2 hours under water,this time duration will allow them to persist & lock on to their prey.They leark under water when ever any animal like wildbeat comes for drinking water,they plung on them the mechanism is really interesting the crocodile heart is designed to pump blood the body parts quickly but it is also programed that during this kind of conditions the heart will provide more blood to limbs & jaws by reducing blood flow to the visceral organs like kidneys,liver etc.So that a crocodile can shoot out with velocity more than 50 or 60 kmph.

After killing the animal is has to cut the meat pieces into chunks this is done by most deadly move of crocodile called the DEATH ROLL.In this process crocodile bites the desired part of the bady & rotates it's body in 360 degrees & around 6-8 turns per minute.

A crocodile can produce an enormus bite fourse of 2000-4000 pounds/inch2,so how does a crocodile produces such enormous bite force the is behind the anatomy of the crocodiles skull,remember the lamarkisam according to this theory the parts which are highly used are modified & biulded but the parts which are not used much will have no or very less development,so crocodiles use their mouth like no other part in their body so legements & tendons have developed more near jaw than near legs so it can produce that much of power in a single bite.

So as you can see the above picture the black circle indicates many number of ligaments(muscle attached to bone) which combine to form a muscle structure around the crocodiles head & a crocodile can open it's mouth maximum of 90 degrees it can't gow beyond as it's jaws are attached to the muscle which will give a restricted movement.

Some time the bite force extends so high that the crocodile can literally loose it's teeth from the socket but there are new set of teeth waiting to come out which can be seen the below picture.

The mouth parts also change along with the food habits in the case of gharial this is a rare evolutionary phenemenon in case of group crocodilia,their snouts are slender & elongated than the slender snouted crocodile.Scientists believe that these crocodiles are completely different from that of all the other 24 verities of the crocodiles & aligators.

(a slender snouted crocodile from africa)

(Gharial crocodile from india)

As you can see in the abouve picture the gharial has very slender snout & so it can feed only on fishes & can't feed on the other animals like the zebra or wildebeest like the nile crocodile feeds on.Since they have slender snouts their bite force is least in crocodila group,that is why it feeds on the fishes.

(gharial eating a cat fish)

Interesting thing is that these crocodiles have large nostrils,it is like a lump like potato with two holes,this allows they to breath even they are lurking under water like the below picture.

Crocodiles which live in the stream of water prefer to open their mouth & just wait for the fish to fall into their mouth near the base of the fall,You can get a dought why is the water not entering into it's stomach,the answer is they close their throat opening to food pipe.

There are evn salt glands present for the crocodile near it's throat to prevent the enty of salt inot the mouth,as they live in fresh water very few in salt water the fluid concentraion is less in the water when compared to the fluid concentraion of the body of crocodile hence it absorbs salts in freah water crocodile while it take place reverse in the merine crocodiles.

These are very great swimmers in reptile world apart from that they are even very accrobatic,they can lift their body off the water to get the food given by the sailer in the boat like the below picture.

They do this on one principle you will feel lighter when you are swimming when compared to land,so they give throttle to their tails this kind of motion is only being done by the tail,as the tail wriggles very quickly than before.As you can see in this picture the crocodile is shooting out of the water but the tail is still in the water this allows they to have stable & shoot out position.This is the other way where they fed by torists.

The bad habit of crocodiles is that they never store food they have plenty of food out there so they hunt have enough of food & rest of the caracus which is floating on the water is being eaten by scavengers in case of african crocodiles like nile or slender snouted crocodile.

SENSORY ORGANS

Crocodile even have sensory organs like integumentory receptors which are present on their snout,these are jelly like substence which catch minute viberation or repulsion in the water this sensory organ is even seen in the sharks these are called ampullae of lorenzini which are present near the mouth of the shark.

As you can see the above picture of shark with ampullae of lorenzini & crocodile with integumentory receptors. This is their major sence organ.

While there are even other sence like hearing,they have the highest power of hearing in the reptile kingdom .

Apart from that they have very high eye sight which will never miss a single move of the prey.

DEFENCE MECHANISM

They really don't need any defence mechanism as they are climax predators meaning they don't have predators in wild,if we take a case of climax predators they are very big of their kind eqipped with finest scense organs in case of fiahes it's shark in case of reptiles it's crocodile & incase of mammals it is lion or tiger or bear.

Crocodiles are naturally armed with heavy tactile shealds like the S.W.A.T.Their body is covered by the bony plates called osteoderms,oseto-bone;derma-skin they have bony plates which make a bony skin on their body with this shield nothing can pierce not even a knife.

So it some thing looks like that in left but it bindes with skin & make crestes on the back so called scales bones on the back.

The modefied & over lapping osetoderms form scutes,these are leaf like strucute which give protection to the crocodile,these are maily present on their abdomen,tail & legs.as shown below.

As you can see in the picture they are leaf like strucute even on the tail or on the leg region,completely crocodiles are covered with bony shield which will ensure perfect protection to the crocodile.
The other defence mechanism is using their deadly jaws to give a deadly bite,aroung 2500-4000 pounds of bite force,with this bone crushing bite there would be no animal which dares to face or mess with crocodiles,they are considered as climax predators

The common defence move of crocodile is not the deadly bite but it's deadly tail swipe,the tail is armed with scutes which are sharp enough to pierce through the skin if sufficient amout of force is five to the tail,but crocodiles are one of the most powerfull reptiles & animal so delivering that force is very easy for it,if that blow is given to the chest human will die on the spot our heart can't sustain that much of force suddenly & so the heart will stop deating causing cardiac arrest.

Though crocodile are very much armed with tough tactile shields on their dorsal surface the poor thing is that they are not armed with either of scutes or oeteoderms on their ventral surface,it is plane
white scaly skin

It is not just the crocodiles it is will all the reptiles from snakes to tuataras even torooises & turtles,even though they have shell the dorsal shell is bigger,better & thicker than the ventral surface
one..

BREEDING & REPRODUCTION

Crocodiles are very good breeders.they may be very harsh with other animals but they are bery kind with their quesins,there is a principle in the nature which is called the fisher's rule this principle states that there are less females in the nature when compared to males,as females tend to give more enery while give birth to the young once so they give off more enery than males in this proces feamles are less in naute this is applicable even for the humans.

Male crocodile impress females by many ways like the bravery,skills most important is romantic.They produce low frequency sounds for impressing females check the video below.

This is an interesting mechanism used for impressing as well as agressive tritorial display,first the crocodile will inhale air expands the chest then sinks just a level below so that only tha back of the crocodile is under the water rest of the body parts like the tail & head are above the water now it exhales air by producing low frequency sounds enabling them to rise the water in drops which fuse with each other to form a ray of water column.This very cool mechanism & there is no animal that can beat crocodile in impressing females.

You may wounder where do crocodiles copulat?.They do in in the water iteslf most of the time,male comes over the female as the picture below

The breeding season is from augest to november the breeding season may vary from specie to specie.After breeding femal crocodiles do not hunt their prey much as the reproductory cycles have begun they rest most of the time & when the time is right they lay eggs near the bacnk of the river or near the shores if it merine specie,usually they dig a considerable amount of hight & length so that all of it's eggs may get suffecient amout of heat to worm the embryo.They are oviparus it mean that they lay eggs containing amnion & embryo.They dig the ground with their rare legs which are very powerful with clows,the eggs come out from the stomatch through the clocal appature which is present in the anal segment which is present near tail portion.

sex determination
The sexes of the baby crocodiles can be known by knkowing the body temperature,it is mechanised that if the body temperature is more the baby is male & if the body temperature is less the baby is female.This the same with agamids too.

structure of egg
As reptiles have lower grade of organisation that mammal or the birds they ley little low organised eggs which have leathery shell unlike birds which have unflexible eggs.This kind of reptilian eggs will with stand more harsh condition than the bird once this is beace of the texture of the shell,this can be explained by simple evolutionary reason the eggs which are in the air in the nest would not face tough challanges as the egg which is presend burried under ground.

                                                            LOCOMOTION
Locomotion in crocodiles is the same to other other reptiles like the lizards which resemble many ways even they move in the same way likcrocodiles do.Crocodiles are like anacongas on land they can't mpve their heavy bodyfrom place to place oftenly like other reptiles,some crocodile like the gharial,slender snouted crocodiles are very good at athletics.

All reptiles except turtles & tortoises move in the water a like snake move in "S" shape manner on land & even on water,lizards also move in the same way but the limbs are sticked to the body while swimming ,crocodiles excute the samething they too move in the "S" shape by keeping their lims sticked to the body.

Crocodiles legs are less evolved than it's tail or it's mouth as it uses it very less,the body part which is used very less will have less evolutionary development than the body part which is frequently used.

Theri tail plays a major role in the locotion of the crocodile in the water for making the 'S' body moverment without the tail it will be incomplete.

                              DIFFERENCE BETWEEN CROCODILE & ALLIGATOR
That is a primary question amoung our society how crocodile diffeerce from an alligator they both seem to look a like in most of the cases like the body structure,pigmentation,body size etc.But there are few characters you need to focus which seperates a crocodile from an alligator.

1.The snout of a crocodile is "V" shaped while an alligators snout is "U" which can be identified easily let us find out.

2.The distribution of the crocodile is around the world but alligators only like in china & america.

3.The upper jaw & the lower jaw fix in the right place in crocodiles while in alligators they don't check the below picture.Crocodile jaws fixes perfect but that is not seen in alligator.

4.In crocodile the tooth which is present in the upper jaw in front protrudes to the bottom but this is not seen in alligators just crocodiles not even caimans.

SPECIES IN THE GROUP CROCODILIA

There are around 23 species of the crocodiles distributed around the world from america to australia.

ASIA

1.Gharial(India)

2.False ghavial(from India to indonesia)

3.Muggar crocodile(India)

4.Saltwater crocodile(through out Asia and Australia)

5.Philippines crocodile( Philippines)

6.New Guinea crocodile(New Guinea)

7.Freshwater crocodile.(Australia)

AFRICA

8.Nile crocodile.(Africa & Madascar)

9.Dwarf crocodile.(Africa)

10.Slender snouted crocodile(south africa)

AMERICA

11.American crocodile.(N.America)

12.Orinoco crocodile.(orinoco river)

13.Cuban crocodile.(Cuban island)

14.Mexican crocodile or Morlet's crocodile(Mexico)

15.Siamese crocodile.(America)

ALLIGATORS

16.American alligator(America)

17.Chinese alligator.(China)

CAIMANS

18.Spectacled caiman(America)

19.Cuver's dwarf caiman(America)

20.Black caiman(America)

21.Yacare caiman(America)

22.Smooth fronted caiman.(America)

23.Broad snouted caiman(America)

Some times an codes foe the albino pigment in the body of the crocodile making the genus of albino superior to the malanin pigment causing rare albinism in the crocodiles very rare.

TESTUDINES

These includes trutles,tortoises & terrapins,there are around 540 species of testudines in the world except in cold places like Antrarctica & greenland.Amoung these highly diversed testudine is the turtle because they live in water & there is no geographical bound to it like the other two have,tortoises & terrapins are less diverse when compared to turtles.

All turtles,terapins & tortoises share a common feature that is the presence of the shell.These are made up of karatin which combine to form a perfect shell.

These are present in order reptilia only because of the presence of the scales & poikiotherms.These are unique reptiles which have features that are un common to reptiles with distinct shells like molluscs.

TURTLES

Most diverse testudine which spread all around the world as they lead an aquatic lifestyle there is no geographical bound to these organisms.

these may be marine or fresh water,body is dosiventrally compressed to form an enclosed shell,shell is nothing but the modified extension of the ribs.Arms are modified to paddles which act as ore while swimming.

They rarly come to the shour only for laying eggs,the largest turtle is the leatherback turtle.

They grow around 6 feet in length very massive wighing around 100-150 kgs,the body is covered by shell which is compressed very much to form a plate like appearence.

The shells of the turtles are compressed unlike tortoises which have very big shells,knowing about shell is very interiguing so lets know about it.

SHELL

Shell is the karetanised extensions of the ribs of the turtle this is same with the tortoises,Shell is connect to the ribs so one can't seperate the shell from the body of the turtle,we can only remove it by killing the turtle itself.The dorsal part of the shell is called the caraphase & the ventral part is called the plastron.

Usually the caraphase is more modified & tough than the plastron,Shells come in different colours orange,black,grey,brown,yellow etc.This is because of the pigment cells present in the shell called as cromatophores which are responisble for giving colour to the shell.

As you can see the above pictures there many different shells around for many different species from soft shell trutle to the green sea turtle.

The shells can mine the age of the turtle as the shells upper curved part has rings called the annual rings present just like in tree,the rigs are added every year allowing us to know the age of the turle.

There is difference between the soft shell & the tough shell,soft shell is soft & can't sustain more force on it but the tough shell is can susatain more force.

Shells are common in both turtles & tortoises these also have some regional names,Shell is nothing but a modified scute so there are scutes like the central scutes present at the centre,Costal scutes present next to the central scute.Vertibral column is just below the central scute & the last one is called the Marginal scute which makes the margin of the shell the border is made of marginal scutes,The caraphase & the plastron combine on the lateral side & form the bridge scales. These are more thick.The subcaudal & the nuchal scutes are present at the opposite sides as seen in the lower picture.

The life of the tortoise can be pridected by it's growth rings which are also called annual rings these rings grow one per year around the margins of the caraphase patern as shown in the below tortoise.

The above picture clearly show that the growth rings do produce & are visible to our eyes.

TORTOISES

These are also called as the land turtle, these are marvilous animal we know very less about their motabilism so unique that it allow them to live one the longest life in animal kingdom.

They exhibit discontinues distribution that means they show distribution in groups as their is geographical restriction unlike turtle which live in water.But they are found through out the world except in the reptilian limited regions like the cold reagons.

Tortoises come in different colours on their shells like yellow,brown,black & many different patterns like boxes,tirangles etc.,The coleration is due to the chromatophores on their shells which will impart the colour to the shell.

Shell of the tortoise differ from the turtle by have a big caraphase more or less the plastron is same in turtles & tortoises,The caraphase is huge as it is a land animal it should have more protection than turtle in course of time it has evolved thicker & bigger caraphase.

Their body anotamy is similar but there physiological features like having more keratinized skin but the skin in the turtle is more soft scally & resperation takes place through the sking in some turtles.Tortoises have legs but the turtle have flippers which are similar to the legs of tortoises.

(Skin of tortoise very thick)

(Skin of turtle soft)

They spend most of their time in the shade & resting these are herbevorous which mainly feed e herds,sherbs etc...They are the slowest reptiles & slowest animals this is one of the reason why they have less metabolic rate & the rate of diffusion of gases or the rate of resperation is very less & this is one of the aspect that has to be noated.The metabolic biproducts that are produced are also different form those of others this is why they live a long life.

These rarely get into water for drinking or any other perpose.

Galapagos Turtoise is the biggest tortoise is the world growing 6 feet in legth & weighs 400 kgs is the heaviest tortoises in the world.

Before continuing further we need to know the classification of the testudins this place an important role in placement of the turtles & tortoises.

There are 2 main suborders called the Pleurodria & Cryptodira.

PLEURODRIA

These are commonly called side necked turtles this is because they contract the vertibral muscle to retract their head.

These are divided into 2 families called chelidae & the Pelomedusidae.

Chelidae

This family includes the side neck turtles like the famous snapping turtles & muta-muta.

This family also includes the some colour full species like the red-headed amazon sideneck turtle & strage species like the toad head turtle.

These are distributed around the world they cover most of the asia & south america.

They may not have teeth but they produce the largest bite force related to it's size it produces around 1002 pounds of bite force.

Pelomedusidae

These are commonly called the Helmeted turtles as they have a helmet lik structure covering their head it is not found in all species but most of them.

This family includes the African side necked turtles which are distrubuted around the Africa unlike the species of chelidae which are distributed around the world

They cannot retract their head directly into the shell but by bending their head they could only withdraw their head up to certain part.

CRYPTODIRA

These are commonly called the Hidde necked turtle,as they retract their head by compressing the muscles of the neck allowing them to retract their neck with a sideways movement either to left or right.

This suborder consist of 3 major superfamilies called the Chelonioidae,Testudinoidae & the Trionychoidae.

Chelonioidae

This superfamily incude families of the leather back turtle which is the largest turtle & cheloniidae which includes the sea turtles like the green sea turtles.These are one of the most diversified testudins in the world covering the entire oceans as their is geographical restriction for the sea animals.

Testudinoidae

This superfamily consist of the familes which include box turtles which are classified in the family called Chelydridae.

This superfamily also includes the largest group the tortoises classified under the family called Testudinidae & old world pond turtles in the family called the Bataguridae.Old wolrd pond turtles are one of the oldest in the Testudinoidae.

Trinoychoidae

This super family includes families like Kinosternidae which includes Mud & muskturtles,it includes american river turtles which are classified under the family Dermatemydidae & soft shell turtles which are in paleotropical areas like the African,Asian forests etc.. are classified under the family Carettochelyidae.

SPHENODONTIA or RHYNCHOCEPHAIA

They are commonly called Tuatara.

The are small sized reptiles which are found in the New Zealand,These are the only 3 eyed reptile of New Zealand.

Tuataras are around 80 cm in length & plae yellow in colours & has spiny crusts on it's back & we can identify this reptile very easily

They live in the forest live a tropical life style it mostly prey on the smaller insects like the grass hopper,crockets & few other food spurses.There where around 200- 300 species of the rhynchocephalia but the have got extinct as course of time as there where many extinctions faced by them but they still have faced it but now only 2 living speacies exists they have being give bu guntheris one of the great herpetologist of 18th century.

These are called a "living fossils" that means that they have not undergone any evolutionary changes for not just 100 or thoughds but millions of years that is very aspect that has to be noated in case of tuataras.

They might look like lizards with a head,trunk & a tail but they have some various features that differ from the lizard one of the most inportant feature is that they don have penis which is a primary copulatory oragan & you might be wondering how do they copulate?

They have clocal appature like all other animals do so the of the clocal appature takes place inorde to tranmist the sperm from male into the femal clocal appature.

The most remarkable feature of them are they have 3 eyes as usual 2 eyes in the orbit in similar position but the 3rd eye is on it's head which has a small lens though it doesn't have better vision through it but through this eye it can navigate the predator whcih are mainly hawks,eagles etc...

As you can see the above picture in course of time they have evolved a meathod of avoiding predator by evolving a 3rd eye as the vision of the lateral eyes are ristricted to their position & motion.

These show old version of the dentation called the acrodent.

Theocodont dentation id seen in the thecodonts remember near the primitive reptiles which gave rose to dimetrodon & thecont.

This group even includes it ancistors like the pleurosaurs,these are marine reptiles which lived in the late jurrasic period This was discovered from the same place where Archeoptryx was discovered that is from germany.

9 comments:

Anonymous said...: Looking good, you have alot of good info here; 17 October 2012 at 07:45
Anonymous said...: many nice details; 17 October 2012 at 22:55
Crystal Poyfair said...: This is a great page! I love how much research you have put into this. Especially by such a young man! Pictures are beautiful and the information is very good. Keep up the good work. You will make an excellent herpetologist, and when I come to your country I would be honored to have you take me field herping!
~Crystal Poyfair
Executive Producer of Herpers 3 and owner of Pioneer Reptiles Herpetological Propagation and Research Center.; 18 October 2012 at 18:48
Steven Khaw said...: This is a great page! I love it, you are excellent!!; 18 October 2012 at 22:48
Scott said...: Nice site!; 21 October 2012 at 21:15
Anonymous said...: Hi Gautman, great blog, loved all the information.; 25 November 2012 at 11:32
Anonymous said...: Great work!! Regards from Spain!!; 10 December 2012 at 10:53
Audrius said...: Thank you for the interesting info! Great page. Good luck to you! Regards from Lithuania.; 12 December 2012 at 00:58
Omar Rafael Regalado Fernández said...: I loved this page. Greetings from a Mexican biologist/palaeontologist; 29 November 2013 at 09:32

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Monday, 15 October 2012

REPTILE ENCYCLOPEDIA.