Why is reptiles cold blooded

Reptiles are cold-blooded, air-breathing vertebrates that have skin covered in scales as opposed to hair or feathers. Amphibians, reptiles, dinosaurs, birds and mammals are all tetrapods and even the limbless snakes are tetrapods by descent. The earliest tetrapods developed from lobe-finned fish, into air-breathing amphibians in the Devonian period. There are around 8, species of reptile on our planet. Today they are represented by four surviving orders:. Ancient reptiles were known as the dinosaurs.

Todays reptiles are much smaller when compared to the gigantic sizes of the Diplodocus or the Brachiosaurus. However, they are all descendants of these magnificent beasts that survived millions of years ago.

Reptiles have existed since the beginning of time. Even snakes were around in the Cretaceous period. Modern reptiles inhabit every continent except for Antarctica, although their main distribution comprises of the tropics and subtropics. There are many species of reptile that survive in Rainforests throughout the globe. California Academy of Sciences. Toggle Close.

Search calacademy. Some of the giant reptiles that ruled the ocean food chain during the time of the dinosaurs may have been able to control their own body temperatures, a new study suggests in the June 11th issue of the journal Science. These reptiles probably had high metabolic rates, which helped them dive deep and swim fast over large distances to catch their prey.

Three large, extinct swimming reptiles, the ichthyosaurs , plesiosaurs and mosasaurs , were the top ocean predators during the Mesozoic era , about to 65 million years ago. Most reptiles today are cold-blooded, meaning their body temperature is determined by how warm or cold their surroundings are.

They compared the oxygen in the reptile teeth with the oxygen in the teeth of fish from the same environments. This tooth oxygen is a clue to an animal's body temperature, because it reflects the composition of oxygen in the blood. If too cold, they may seek a sunny spot to warm up. In colder months, most temperate species seek a place with a lower than optimum yet fairly stable temperature, allowing their metabolisms to slow down so they require little or no food, and wait for better conditions to come back like spring.

But what about hibernating bears, you may ask. And of course, this short ish discussion is streamlined for the sake of time and space! I hope to see you visiting all of the wonderful ectotherms and endotherms that reside at Zoo Atlanta!

Robert Hill Assistant Curator of Herpetology. Generic filters Hidden label. Hidden label.