Captorhinidae (also known as cotylosaurs, or 'stem reptiles') were one of the earliest and most basal reptiles. They are a clade of small lizard-like reptiles that date from the late Carboniferous through the Permian. Their skulls were much stronger than their relatives, the Protorothyrididae, and had teeth that were better able to deal with tough plant material.

Life restoraton of Labidosaurus hamatus. Captorhinids have broad, robust skulls that are generally triangular in shape when seen in dorsal view. The premaxillae are characteristically downturned. Early, smaller forms possessed single rows of teeth, while larger, more derived forms such as Captorhinus and Moradisaurus possessed multiple rows of teeth.