Austronaga

Austronaga (meaning "southern naga") is an extinct genus of dinocephalosaurid archosauromorph reptile from the Middle Triassic (Anisian) Guanling Formation of China. The genus contains a single species, A. minuta, known from a partial skull, as well as vertebrae from the tail and neck. Austronaga was significantly smaller than the coeval Dinocephalosaurus.

Discovery and naming
The Austronaga holotype specimen, IVPP V18579, was discovered in sediments of the Guanling Formation (Member II), which has been dated to the Anisian age (Pelsonian substage) of the middle Triassic period, near Waina Village in Luoping County of Yunnan Province, China. The incomplete specimen preserves a nearly complete skull articulated with the first six cervical vertebrae, as well as sixty-five caudal vertebrae.

In 2023, Wang, Lei & Li described Austronaga minuta as a new genus and species of tanystropheid archosauromorph based on these fossil remains. The generic name, "Austronaga''", combines the Latin word "austral", meaning "southern", in reference to the type locality in the South China Block, with "naga", referencing a water-dwelling snakelike figure in Asian mythology. The specific name, "minuta", references the animal's small body size compared to its relatives.

Classification
Wang, Lei & Li (2023) recovered Austronaga as a member of the Dinocephalosauridae, as the sister taxon to Dinocephalosaurus. The results of their phylogenetic analyses are shown in the cladogram below: