Reptile eggs and amphibian eggs look nothing alike once you know what to look for. A reptile egg has a shell, like a bird's egg. An amphibian egg is a blob of jelly, like a fish's egg. That difference decides where each kind of animal can live and breed. Reptiles (snakes, lizards, turtles, crocodilians, and the tuatara) lay amniotic (am-nee-OT-ik) eggs. Inside, the baby floats in a bag of fluid called the amnion. You had one of those too, before you were born. The yolk holds the baby's food. Another sac, the allantois, handles breathing, trading oxygen and carbon dioxide through the shell. In species that give birth to live young, the mother's body does that job instead.
This lesson is part of Certified Junior Herpetologist. Enrollment is self-paced, with no deadline to finish (about 30 hours).
