Chouioia

Chouioia is a genus of extinct, primitive reptilian diapsids from the Middle Triassic period of China. It is known from a single species, Chouioia lubeiensis.

Fossils of Chouioia have been found in the Heshanggou Formation of Shanxi Province, China. The genus is significant because it provides insights into the early evolution of diapsids, the reptilian lineage that includes lizards, snakes, crocodiles, and birds.

Chouioia possessed a slender body and relatively long limbs, suggesting a terrestrial lifestyle. Its skull structure exhibits features considered to be intermediate between more basal diapsids and later, more derived forms. These features are important for understanding the phylogenetic relationships within Diapsida and the diversification of this group during the Triassic period.

The exact placement of Chouioia within Diapsida is still debated among paleontologists. Some analyses suggest that it may be closely related to the lineage leading to lepidosaurs (lizards and snakes), while others place it closer to archosauromorphs (the group including crocodiles, dinosaurs, and birds). Further research and fossil discoveries are necessary to fully resolve its evolutionary relationships.

Chouioia lubeiensis was named by Li in 1989. The name "Chouioia" refers to the Chouiou locality where the fossils were discovered, and "lubeiensis" refers to Lubei, another nearby location.