A revision of fossil turtles from the Kiev clays (Ukraine, middle Eocene) with comments on the history of the collection of fossil vertebrates of A.S. Rogovich

Abstract

The paper revises material of fossil turtles from the Kiev clays (Vyshgorod and Tripolye localities, Kiev Province, Ukraine; Kiev Formation, upper Lutetian – lower Bartonian, middle Eocene) from the 19th century collection of fossil vertebrates of the Russian naturalist A.S. Rogovich. In the course of more than a century this collection was divided into parts several times and stored in different institutions of Moscow, Saint Petersburg, and Kiev. The turtle material from Rogovich’s collection includes a partial skeleton and isolated shell fragments from Vyshgorod locality referred here to a pancheloniid sea turtle Argillochelys antiqua (Konig, 1825), a species formerly known only from the Paleogene of Western Europe, partial dentaries from Vyshgorod locality, belonging to “Dollochelys” rogovichi Averianov, 2002, a pancheloniid with unclear generic attribution, and sculptured shell fragments of Pan-Cheloniidae indet. from Tripolye locality, erroneously assigned to a crocodile by Rogovich. The material of A. antiqua unites some specimens previously described as Puppigerus sp. and Dollochelys rogovichi, as well as newly revealed specimens. According to our interpretation, parts of the skeleton of A. antiqua from Vyshgorod locality were stored in different institutions for a long time, sharing the fate of the whole Rogovich’s collection of fossil vertebrates. The attribution of the Vyshgorod material to A. antiqua is supported by phylogenetic analysis of pancheloniids. This analysis also demonstrates an Argillochelys clade (A. antiqua + A. cuneiceps [Owen, 1849]), and removes “A.” africana Tong et Hirayama, 2008 from this clade. Analysis of the geographic and stratigraphic distribution of the genus Argillochelys shows that it is restricted to the ?Thanetian – Priabonian of the Peri-Tethyan area (Western and Eastern Europe and Kazakhstan) and possibly also to eastern North America. In addition, our study shows that sculptured pancheloniids of unknown affinities are quite common in the middle Eocene of Eastern Europe and Central Asia.