Answer: thecodonts

AnswerCrossword Clue
thecodontsA fossil quadrupedal or partly bipedal reptile of the Triassic period, having teeth fixed in sockets in the jaw. Thecodonts are ancestral to the dinosaurs and other archosaurs
thecodontsTHECODONT, a member of the order Thecodontia of archosaurian reptiles with teeth fixed in sockets in the jawbone