Austronaga

Not to be confused with Austrosaga.

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.^[1]

Austronaga Temporal range: Middle Triassic (Anisian) PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauromorpha
Clade:	†Tanysauria
Family:	†Trachelosauridae
Genus:	†Austronaga
Species:	†A. minuta
Binomial name
†Austronaga minuta Wang, Lei & Li, 2023

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.^[1]

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.^[1]

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:^[1]

Archosauromorpha	Protorosaurus Prolacerta Crocopoda Macrocnemus fuyuanensis Macrocnemus bassanii Fuyuansaurus Elessaurus Augustaburiania Macrocnemus obrisi Dinocephalosauridae Pectodens Austronaga Dinocephalosaurus Tanystropheidae Amotosaurus Tanystropheus longobardicus Tanystropheus hydroides Raibliania Gracilicollum Sclerostropheus Tanytrachelos Ozimek Langobardisaurus

References

1. Wang, W.; Lei, H.; Li, C. (2023). "A small-sized dinocephalosaurid archosauromorph from the Middle Triassic of Yunnan, southwestern China". Vertebrata PalAsiatica. doi:10.19615/j.cnki.2096-9899.231013.