Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class Sauropsida. Today they are represented by four surviving orders:
Anapsid Synapsid Amniote Diapsid Crocodilia Paraphyly Squamata Turtle Mammal Sphenodontia Sauropterygia Vivipary Ichthyosaur Tuatara Archosaur Testudines Millerettid Pterosaur Younginiformes Araeoscelidia Edwin Stephen Goodrich Amphisbaenia Lepidosauromorpha Lepidosauria Bird Dinosaur Archosauromorpha Ovoviviparity Thoracic diaphragm Cladistics Carboniferous Clade Alligator Embryo Crocodile Lizard Vertebrate Snake Lists of reptiles by region Reabsorption
