Definition of cotylosaur
: any of an order (Cotylosauria) of extinct primitive reptiles of the Carboniferous to Triassic with short legs and massive bodies that were prob. the earliest truly terrestrial vertebrate animals
Origin and Etymology of cotylosaur
ultimately from Greek kotylē + sauros lizard
First Known Use: 1895
Seen and Heard
What made you want to look up cotylosaur? Please tell us where you read or heard it (including the quote, if possible).