What Are the Similarities Between Reptiles and Amphibians?

Reptiles and amphibians are both cold-blooded invertebrates in addition to having number of other features in common. The two groups also reproduce by laying eggs instead of carrying live young as mammals do.

The fact that they are cold-blooded means that reptiles and amphibians don't have the ability to internally regulate their body temperature, and instead warm their bodies by absorbing heat from the sun and their surroundings. Both reptiles and amphibians regularly shed their skin, with many frogs, salamanders and toads doing this as often as once a week. Most amphibians eat their skin after shedding it, while reptiles leave their discarded skin behind.

Although both groups lay eggs, the eggs they lay are quite different. Amphibians have small, jelly-like eggs that must be covered in water to hatch, while reptile eggs have a leathery shell and usually need to remain dry to successfully hatch. Another difference is that reptiles are born fully formed, while amphibians start off life as a tadpole or other immature form, before slowly metamorphosing into an adult.

Both reptiles and amphibians can be found on every continent except Antarctica and live in a wide variety of climates. Despite their need for water, amphibians are also found in quite dry climates, just like reptiles.