A redescription of Elkemys australis (Yeh, 1974), a poorly known basal testudinoid turtle from the Paleocene of China

I.G. Danilov, J. Claude and V.B. Sukhanov

Proceedings of the Zoological Institute RAS, 2012, 316(3): 223–238 · https://doi.org/10.31610/trudyzin/2012.316.3.223

Full text

Abstract

In this study we provide a redescription of the type series of Elkemys australis, a poorly known basal testudinoid turtle (‘Lindholmemydidae’) from the Paleocene of China. Based on new observations we report on some previously overlooked shell characters of Elkemys australis, and also provide a new diagnosis and a new reconstruction for this species. Among ‘lindholmemydids’, Elkemys australis is most similar to Gravemys barsboldi from the Late Cretaceous of Mongolia. Elkemys australis, Gravemys spp. and Hokouchelys chenshuensis from the Paleocene of China differ from other ‘lindholmemydids’ and testudinoids in general in an unique inframarginal pattern (four or five pairs of wide inframarginal scutes which strongly extend on to peripherals), and may form a natural group (either a clade or a grade) of basal testudinoids. Some other characters shared by E. australis, G. barsboldi and H. chenshuensis (large anal notch and relatively narrow vertebrals 2 and 3) are characteristic of some geoemydids and testudinids, that may indicate closer relations of the three mentioned genera to these groups.

Key words

China, Elkemys, ‘Lindholmemydidae’, Paleocene, Testudinoidea, Turtles

Submitted June 15 , 2012 · Accepted August 15, 2012 · Published September 25, 2012

References

Brinkman D.B., Li J. and Ye X. 2008. Order Testudines. In: J. Li, X. Wu and F. Zhang (Eds.). The Chinese Fossil Reptiles and Their Kin. Second edition. Science Press, Beijing: 35–102.

Chkhikvadze V.M. 1976. New data on fossil turtles of Mongolia, China and Eastern Kazakhstan. Bulletin of the Academy of Sciences of the Georgian SSR, 82: 745–748. [In Russian].

Chkhikvadze (Čkhikvadze) V.M. 1984. Classification des tortues de la famille des Emydidae et leurs liens phylogénétiques avec d’autres familles. Studia Palaeocheloniologica, 1: 105–113.

Chkhikvadze (Čkhikvadze) V.M. 1987. Sur la classification et les caractères de certaines tortues fossiles d’Asie, rares et peu étudiées. Studia Palaeocheloniologica, 2: 55–86.

Claude J. and Tong H.2004. Early Eocene testudinoids from Saint-Papoul, France with comments on the early evolution of basal testudinoids. Oryctos, 5: 3–45.

Danilov I.G. 1999. A new lindholmemydid genus (Testudines: Lindholmemydidae) from the mid-Cretaceous of Uzbekistan. Russian Journal of Herpetology, 6: 63–71.

Danilov I.G. 2001. Morphology of early testudinoids and relationships of cryptodiran turtles. Journal of Vertebrate Paleontology (3, Supplement): 43A.

Danilov I.G. 2003. Gravemys Sukhanov et Narmandakh, 1983 (Testudinoidea: Lindholmemydidae) from the Late Cretaceous of Asia: new data. Paleobios, 23(3): 9–19.

Danilov I.G. 2005a. Die fossilen Schildkröten Europas. In: U. Fritz (Hrsg.). Handbuch der Reptilien und Amphibien Europas. Schildkröten II (Cheloniidae, Dermochelyidae, Fossile Schildkröten). Aula-Verlag, Wiebelsheim: 329–441.

Danilov I.G. 2005b. Early testudinoids turtles of Asia and their position in the system. Modern Paleontology: Classical and New Methods. The Second All-Russian Scientific School for Young Scientists in Paleontology (3–5 October, 2005, Moscow, Russia). Abstracts: 23–24. [In Russian].

Danilov I.G., Bolotsky Yu.L., Averianov A.O. and Donchenko I.V. 2002. A new genus of lindholmemydid turtle (Testudines: Testudinoidea) from the Late Cretaceous of the Amur River Region, Russia. Russian Journal of Herpetology, 9: 155–168.

Danilov I.G. and Sukhanov V.B. 2001. New data on lindholmemydid turtle Lindholmemys from the Late Cretaceous of Mongolia. Acta Palaeontologica Polonica, 46: 125–131.

Gaffney E.S. and Meylan P.A. 1988. A phylogeny of turtles. In: M.J. Benton (Ed.). The Phylogeny and Classification of the Tetrapods. Vol. 1. Oxford University Press, New York: 157–219.

Hay O.P. 1908. The Fossil Turtles of North America. Carnegie Institute of Washington Publications, 75: 1–568. https://doi.org/10.5962/bhl.title.12500

Hervet S. 2004. Systématique du groupe “Palaeochelys sensu lato – Mauremys” (Chelonii, Testudinoidea) du Tertiaire d’Europe occidentale: principaux résultats. Annales de Paléontologie, 90: 13–78. https://doi.org/10.1016/j.annpal.2003.12.002

Hirayama R. 2000. Fossil turtles. In: H. Matsuoka (Ed.). Fossils of Kuwajima “Kaseki-kabe” (Fossil-bluff): Scientific Report on a Neocomian (Early Cretaceous) Fossil Assemblage from the Kuwajima Formation, Tetori Group, Shiramine, Ishikawa, Japan. Shiramine Village Board of Education, Ishikawa Prefecture, Japan: 75–92. [In Japanese, English abstract].

Hirayama R., Brinkman D. and Danilov I. 2000. Distribution and biogeography of non-marine Cretaceous turtles. Russian Journal of Herpetology, 7: 181–198.

Joyce W.G. and Bell C.J. 2004. A review of comparative morphology of extant testudinoid turtles (Reptilia: Testudines). Asiatic Herpetological Research, 10: 53–109.

Khosatzky L.I. and Młynarski M. 1971. Chelonians from the Upper Cretaceous of Gobi Desert, Mongolia. Palaeontologica Polonica, 25: 131–144.

Lapparent de Broin F. de. 2001. The European turtle fauna from the Triassic to the Present. Dumerilia, 4: 155–217.

Lourenco J.M., Claude J., Galtier N. and Chiari Y. 2012. Dating the cryptodiran nodes: origin and diversification of the turtle superfamily Testudinoidea. Molecular Phylogenetics and Evolution, 62: 496–507. https://doi.org/10.1016/j.ympev.2011.10.022

Lucas S.G. 2001. Chinese Fossil Vertebrates. Columbia University Press, New York, 375 p. https://doi.org/10.7312/luca08482

McDowell S.B. 1964. Partition of the genus Clemmys and related problems in the taxonomy of the aquatic Testudinidae. Proceedings of the Zoological Society of London, 143: 239–279. https://doi.org/10.1111/j.1469-7998.1964.tb03860.x

Parham J.F., Feldman C.R. and Boore J.L. 2006. The complete mitochondrial genome of the enigmatic bigheaded turtle (Platysternon): description of unusual genomic features and the reconciliation of phylogenetic hypotheses based on mitochondrial and nuclear DNA. BMC Evolutionary Biology, 6(11): 1–11. https://doi.org/10.1186/1471-2148-6-11

Pritchard P.C.H. 1988. A survey of neural bone variation among recent chelonian species, with functional interpretations. Acta Zoologica Cracoviensia, 31(26): 625–686.

Riabinin A.N. 1935. Remains of a turtle from the Upper Cretaceous deposits of the Kizylkum Desert. Trudy Paleozoologicheskogo Instituta, 4: 69–77. [In Russian].

Shuvalov V.F. and Chkhikvadze V.M. 1975. New data on the Late Cretaceous turtles of South Mongolia. Trudy Sovmestnoy Sovetsko-Mongol’skoy Paleontologicheskoy Ekspeditsii, 2: 214–229. [In Russian].

Shuvalov V.F. and Chkhikvadze V.M. 1979. On stratigraphic and systematic position of some freshwater turtles from new Cretaceous localities in Mongolia. Trudy Sovmestnoy Sovetsko-Mongol’skoy Paleontologicheskoy Ekspeditsii, 8: 58–76. [In Russian].

Sukhanov V.B. 2000. Mesozoic turtles of Central Asia. In: M.J. Benton, M.A. Shishkin, D.M. Unwin and E.N. Kurochkin (Eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge University Press, Cambridge: 309–367.

Sukhanov V.B., Danilov I.G. and Narmandakh P. 1999. A new lindholmemydid turtle (Testudines: Lindholmemydidae) from the Bayn Shire Formation of Mongolia. Russian Journal of Herpetology, 6: 147–152.

Sukhanov V.B. and Narmandakh P. 1976. Paleocene turtles of Mongolia. Trudy Sovmestnoy Sovetsko-Mongol’skoy Paleontologicheskoy Ekspeditsii, 3: 107–133. [In Russian].

Sukhanov V.B. and Narmandakh P. 1983. A new genus of the Late Cretaceous turtles of Mongolia. Trudy Sovmestnoy Sovetsko-Mongol’skoy Paleontologicheskoy Ekspeditsii, 24: 44–66. [In Russian].

Sun A., Li J., Ye X., Dong Zh. and Hou L. 1992. The Chinese Fossil Reptiles and Their Kins. Science Press, Beijing-New York, 260 p.

Yeh H.K. 1974. Cenozoic chelonian fossils from Nanhsiung, Kwangtung. Vertebrata PalAsiatica, 1: 26–37.

Yeh H.K. 1994. Fossil and Recent Turtles of China. Science Press, Beijing, 112 p.