A new broad-snouted fossil carettochelyid turtle from a previously unknown Caenozoic deposit in Sarawak, Malaysia

Abstract

Fossils of pan-carettochelyid turtles are known from most continents of the world, except Antarctica. The fossils that have been described indicate a group of estuarine turtles that have little modified their body form since the Cretaceous. The only species for which ecological data exist is the extant Carettochelys insculpta, found in estuarine or fresh waters in Australia and New Guinea. Here we report the discovery of an incomplete skull of a previously unknown carettochelyid Carettochelys niahensis sp. nov. from an undated fossil deposit within or beneath a Miocene marine limestone formation in Niah Great Cave, Sarawak, Malaysia. The skull exhibits many anatomical features characteristic of this turtle group but differs from previously known taxa in that it has a broad, nasal orifice that is proportionately wider than in other carettochelyids and relatively shallow but wider temporal arches. Some aspects of the palaeoecology of this turtle are inferred.

Arthur White [[email protected]] Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia;

Michael Archer [[email protected]] Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia;

Suzanne J. Hand [[email protected]] Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia;

Henk Godthelp [[email protected]];

Anna K. Gillespie [[email protected]] Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia.

Keywords:

• Carettochelys
• Carettochelyidae
• Sarawak
• turtle
• palaeoecology
• biogeography

Acknowledgements

The Australian Research Council provided funding to SJH and MA for palaeontological and zoological research in Sarawak. We thank Sarawak’s State Secretary of the Chief Minister’s Office, Director of SM, Director of Forestry, and Director of National Parks for their support and help in obtaining permits and organizing contacts during our research. The rangers and staff in Niah National Park were also very helpful during site inspection and fossil collecting. We thank Wong Siew Fui (SM) and G. M. Drawhorn (California State University Sacramento), for assisting with specimen registration and advice. Constructive criticism by Serjoscha Evers (University of Freiburg) and an anonymous reviewer greatly improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).