Meyasaurus faurai (Vidal 1915, M. dizromerali Evans and Barbadillo 1996) Early Cretaceous, ~10 cm skull length was considered an early lizard and a sphenodontid, but with the first rib atypically (for lizards) associated with the fifth vertebra. Here Meyasaurus was derived from a sister to Carusia near the base of the protosquamates. Meyasaurus phylogenetically was derived from Daohugo lizard.
Distinct from the Daohugou lizard, the skull of Meyasaurus had a more sharply angled rostrum. The postorbital did not descend as far. The premaxilla dorsal process extended beyond the naris. The frontal was narrower between the orbits. Like Carusia, the teeth were tiny and the posterior teeth had twin cusps (bicuspid). The cervicals of Meyasaurus were more robust with large paddle-shaped ribs. The scapulocoracoid was fenestrated anteriorly, as in all other lizards, and the clavicle was more robust. The humerus was expanded distally. Metacarpal 4 was shorter than 3. A purported juvenile had similar proportions.
See the complete tree.