Expert annotations for this species! See the animations.

Pelusios sinuatus, the East African serrated mud turtle (Zug, 1993; Iverson, 1992; King and Burke, 1989), is a side-necked turtle, or pleurodire, of the clade Pelomedusidae. P. sinuatus is known from Somalia southward to Zululand, Transvaal, Natal, and west to Lake Tanganyika and Victoria Falls.

As currently interpreted (Meylan, 1996; de Broin, 1988), Pelomedusidae consists only of Pelusios and Pelomedusa, both extant. Pelomedusidae is hypothesized to be the sister group to Bothremydidae (extinct) and Podocnemididae (which includes Podocnemis and Hamadachelys) because the latter two have a quadrate-basioccipital contact absent in pelomedusids and other pleurodires (Tong, Gaffney, and Buffetaut, 1998). Also, in pelomedusids like Pelusios, the carotid enters the skull through the prootic (coronal slice #325), a primitive condition found in chelids, which are the outgroup to Pelomedusoides (Pelomedusidae + Bothremydidae + Podocnemididae).

This specimen, a zoo animal with no locality data, was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Gene Gaffney of the American Museum of Natural History and Dr. George Zug of the National Museum of Natural History, in collaboration with Dr. Timothy Rowe of The University of Texas at Austin. Funding for scanning was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Rowe.

The specimen was scanned by Richard Ketcham and Matthew Colbert on 30 October 2000 along the coronal axis for a total of 495 slices, each slice 0.1375 mm thick, with an interslice spacing of 0.1375 mm. The animations displayed below were reduced for optimal Web delivery from the original, much higher resolution CT data. Several unreduced sample CT slices are presented to illustrate some key anatomical features of Pelusios along with annotations. See the annotated movies.

de Broin, F. 1988. Les Tortues et le Gondwana. Studia geologica Salamanticensia. Studia Palaeochelonologica II:103-142.

Ernst, C. H., and R. W. Barbour. 1989. Turtles of the World. Smithsonian Institution Press, Washington, D.C., 313 pp.

Gaffney, E. S. 1972. An illustrated glossary of turtle skull nomenclature. American Museum Novitates 2486:1-33.

Gaffney, E. S. 1979. Comparative cranial morphology of recent and fossil turtles. Bulletin of the American Museum of Natural History 164:65-376.

Gaffney, E. S. 1990. Comparative osteology of the Triassic turtle Proganochelys. Bulletin of the American Museum of Natural History 194:1-263.

Gaffney, E. S., and P. A. Meylan. 1988. A phylogeny of turtles; pp. 157-219 in M. J. Benton (ed.), The Phylogeny and Classification of the Tetrapods, Volume 1: Amphibians, Reptiles, Birds. Systematics Association Special Volume 35A, Clarendon Press, Oxford.

Iverson, J. B. 1992. A revised checklist with distribution maps of the turtles of the world. Privately printed, Richmond, Indiana, 363 pp.

King, F. W., and R. L. Burke. 1989. Crocodilian, Tuatara, and turtle species of the world, a taxonomic and geographic reference. Association of Systematic Collections, Washington, D. C., 216 pp.

Meylan, P. A. 1996. Skeletal morphology and relationships of the early Cretaceous side-necked turtle, Araripemys barretoi (Testudines: Pelomedusoides: Araripemydidae), from the Santana Formation of Brazil. Journal of Vertebrate Paleontology 16:20-33.

Pough, F. H., R. M. Andrews, J. E. Cadle, M. L. Crump, A. H. Savitzky, and K. D. Wells. 1998. Herpetology. Prentice Hall, Upper Saddle River, New Jersey, 577 pp.

Tong, H., E. S. Gaffney, and E. Buffetaut. 1998. Foxemys, a new sidenecked turtle (Bothremydidae: Pelomedusoides) from the late Cretaceous of France. American Museum Novitates 3251:1-19.

Zug, G. 1993. Herpetology, an Introductory Biology of Amphibians and Reptiles. Academic Press, San Diego, 527 pp.

Links

The Chelonian Research Foundation

The Tortoise Trust

Gene Gaffney's Phylogeny of Turtles (AMNH) (requires Flash plug-in)