300861 Lecture Notes - Lecture 13: Allantois, Internal Fertilization, Quadrupedalism
17 May 2019
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Document Summary
They have internal fertilization, amniotic development (in which the embryo develops within a set of protective extra-embryonic membranes the amnion, chorion, and allantois), and epidermal scales covering part or all of their body. The major groups of living reptiles the turtles, tuataras, lizards and snakes, and crocodiles account for over 8,700 species. Reptiles evolved from amphibians during the first part of the. Pennsylvanian subperiod (323 million to 299 million years ago) and retained many amphibian structural characteristics. While most reptiles feed on other organisms, a few are herbivorous (e. g. , tortoises). As cold-blooded animals, reptiles tend to be limited to temperate and tropical areas, but, where they occur, they are relatively common; however, they are not as large or conspicuous as birds and mammals. Most reptiles are terrestrial, but a few are aquatic. They move about by creeping or swimming in a fashion similar to amphibians.
