Watson believed that the jaw of dimetrodon was capable of anteroposterior sliding.
The adductor musculature of the lower jaw in dimetrodon was divided into lateral and medial groups (Figs. 5, 6).
A comparison of the general pattern of the adductor musculature of Captorhinus and dimetrodon reveals an expected similarity.
A similar origin suggests itself for the corresponding muscle, the second major adductor mass, in dimetrodon.
The dentition of dimetrodon further substantiates the movement of the jaw in a simple up and down direction.
Evidence for the presence and extent of a pseudotemporal muscle in both Captorhinus and dimetrodon is lacking.
An extinct, carnivorous reptile of the genus Dimetrodon of the Permian Period having a body similar to an alligator's but with a tall, curved sail on its back. The sail had a thick network of blood vessels and may have been used to regulate the animal's body temperature. The dimetrodon belonged to the synapsids, an early group of reptiles that was ancestral to mammals.