Vertebrates: Reptiles

Reptiles are found on every continent except for Antarctica. They appeared around 340 million years ago. Lizards and snakes, turtles and tortoises, crocodiles and alligators, and tuatara are the four groups of reptiles. So what makes a reptile a reptile?

 

The two biggest clues are:

1.    They are cold-blooded, and

2.    They are covered in scales.

Being cold-blooded means that they can't regulate their own body temperature, their bodies react to the temperature of their surroundings.  When they get too warm, they can go into the water or shade to cool off. When they get too cold they can hang out in the sun to warm themselves up.  While scales protect their bodies, scales can be hard or soft, large or small.

Reptiles are air-breathing animals, although many live not only on land but in water. The majority of reptiles laid eggs to give birth to their young. Reptiles are born on land and are born with strong instincts, so they are on their own at birth.  Just think, no parents to nag them about cleaning their rooms!

 

Although reptiles breathe through lungs, some reptiles can also absorb oxygen in water through membranes in their mouth.