Jesairosaurus lehmani (Jalil 1997) Early to Middle Triassic ~240 mya was originally described as a prolacertiform and thus related to Prolacerta. Here Jesairosaurus is derived from a sister to the Palaegama and is a sister to Hypuronector and the Drepanosauridae.
Distinct from Palaegama, the skull of Jesairosaurus was larger, the neck was shorter, the torso larger and the limbs shorter. The quadrate leaned anteriorly.
The torso was wider than tall. More than thirty dorsal vertebrae were present. Four sacrals were present. The caudal series (only the anterior three vertebrae are known) was gracile. Gastralia were present here, but not on sister taxa even several nodes away. The fibula was appressed to the tibia.
With ancestors and descendants arboreal, Jesairosaurus was also likely arboreal.