Nanhsiungchelyidae ( or ) is an extinct family of land

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

s known from Cretaceous deposits in Asia and North America. Nanhsiungchelyids were more terrestrial than many of their contemporaries, and may have gone extinct at the end of the Cretaceous as a result.

Classification

The name Nanhsiungchelyidae was coined by Yeh in 1966, in the same paper in which the type genus ''Nanhsiungchelys'' was described. The name is derived from the name of the type species, with the suffix of a family, -idae, added to it.

Taxonomy

According to phylogenetic analyses, Nanhsiungchelyidae is the sister group to

Adocidae The Adocidae are an extinct family of aquatic and omnivorous turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups ...

, and thus both are included within the clade Adocusia. Nanhsiungchelyidae is split into two major clades, one including most of the predominantly Asian species (''Jiangxichelys'', ''Anomalochelys'', etc.) and a clade including only the different species within the genus ''Basilemys''. When looking at recent analyses, it also becomes clear that some of the species of ''Zangerlia'' might not be the same genus, as the type species confidently gets placed in a very different position than the other two valid species.

Phylogeny

Multiple phylogenetic analyses have been conducted on Nanhsiungchelyidae, but one of the most recent analyses comes from Tong & Li (2018). In this analysis, we see 13 Nanhsiungchelyid taxa represented, with ''Adocus'' used as an outgroup. ''Nanhsiungchelys'' and ''Anomalochelys'' are recovered as being in a clade together in nearly every analysis, and the same goes for the different species of ''Basilemys''. However, the placement of the different species of ''Zangerlia'' varies a lot between publications. Before the redescription of ''Nanhsiungchelys'' in 2018, the different species of ''Zangerlia'' were often recovered as being in a clade together, on the opposite side of the ''Basilemys''-clade. This can be seen in papers like Sullivan ''et al.'' (2013) and Sukhanov, Danilov & Syromyatnikova (2008). However, the phylogenetic analysis in Tong & Li (2018) does not recover this clade, instead spreading the different species out in the tree, recovering the type species as closer to ''Adocus'' than the others, which are placed in the clade that includes ''Jiangxichelys'', ''Hanbogdemys'', ''Anomalochelys'' and ''Nanhsiungchelys''. Phylogeny after Tong & Li (2018)

References

Trionychia Cretaceous turtles Extinct turtles Prehistoric reptile families {{Cretaceous-reptile-stub