New data on the soft-shelled turtles from the Upper Cretaceous Kyrkkuduk I locality of Southern Kazakhstan

N.S. Vitek and I.G. Danilov

Proceedings of the Zoological Institute RAS, 2012, 316(1): 50–56 · https://doi.org/10.31610/trudyzin/2012.316.1.50

Full text

Abstract

We re-examine one previously described trionychid specimen (a posterior part of a carapace formerly attributed to Trionyx zakhidovi Khosatzky, 1966) and describe additional trionychid shell material from the Upper Cretaceous (Santonian – ?Middle Campanian) Kyrkkuduk I locality (= Sary-Agach) in southern Kazakhstan. All material was collected by the Russian geologist and paleobotanist V.D. Prinada in the 1920s. Based on new observations and material, we refer much of the material from Kyrkkuduk I to “Trionyx” kansaiensis Vitek et Danilov, 2010, a shell taxon known from the Late Cretaceous of Tadzhikistan and Kazakhstan. The remaining material is assigned to a second trionychid taxon that is similar to some members of the tribe Trionychini from the Late Cretaceous of Asia, but is identified conservatively as Trionychidae indet. Thus, we confirm the presence of at least two forms of trionychids in the Kyrkkuduk I locality, as was previously proposed by earlier authors, although our taxonomic identifications differ. The newly referred material of “Trionyx” kansaiensis expands the geographic range of this species and provides new information about its morphology, especially the structure of the xiphiplastron and variation of the neurals.

Key words

Asia, Kazakhstan, Trionychidae, turtles, Upper Cretaceous

Submitted February 3, 2012 · Accepted February 27, 2012 · Published March 23, 2012

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