[kot-l-uh-sawr] 
| any member of the extinct order Cotylosauria, comprising heavy-bodied, splay-limbed, plant-eating reptiles that arose during the Carboniferous Period and that are considered to include the ancestors of all other reptiles. |
| cot·y·lo·saur (kŏt'l-ə-sôr') n. Any of an extinct order (Cotylosauria) of massive primitive reptiles of the Carboniferous and Permian periods that included the ancestors of all of the reptiles. Also called root reptile, stem reptile. [Greek kotulē, hollow object, socket + Greek sauros, lizard.] |
| cotylosaur (kŏt'l-ə-sôr') Pronunciation Key
Any of a number of extinct reptiles of the group Cotylosauria or Captorhinida of the Carboniferous and Permian Periods that include the ancestors of all terrestrial vertebrates except for amphibians. Cotylosaurs evolved from early amphibians, had four sprawling legs and a long tail, and a skull without temporal openings. Also called stem reptile. |