Vertebrata

(the vertebrates)

Basal Vertebrates (Fish)

Tetrapods
---Stem Tetrapods
---Amphibia (Frogs, salamanders, caecilians)
---Anapsida (Turtles, etc.)
---Diadectomorpha
---Diapsida (Reptiles, Dinosaurs, Birds)

Archosauria (Dinosaurs, crocodiles, birds)
Ichthyopterygia (Ichthyosaurs)
Sauropterygia (plesiosaurs, nothosaurs)
Sphenodontidae (tuatara & kin)
Squamata (Lizards, snakes, etc.)
---Synapsida (Mammals & kin)
Cynodonts
---Basal Cynodonts
---Mammalia (Mammals)
Dicynodontia
Dinocephalia
Gorgonopsia
"Pelycosaurs" (basal synapsids)