CAPTORHINUS

genus of extinct reptiles found as fossils in Permian rocks of North America (the Permian Period lasted from 286 to 245 million years ago). Captorhinus was small with slender limbs; its full length was about 30 cm (12 inches), and its skull was only about 7 cm (2.75 inches) long. It bore some resemblance to a modern lizard. Captorhinus was one of the earliest and most primitive reptiles. In form it was representative of the captorhinomorphs (order Cotylosauria), a suborder of early reptiles with nearly solid skulls that had no openings for the attachment of jaw muscles. The captorhinomorphs were eventually succeeded by reptiles with more advanced skulls and stronger jaws for biting and chewing food. The captorhinomorphs nevertheless persisted into the Late Triassic Epoch (230 to 208 million years ago) before becoming extinct.