Cynomys ludovicianus, the black-tailed prairie dog, is known from the late Rancholabrean to the Recent of the central and southern Great Plains, with a modern distribution from Canada to northern Mexico. In all, eight species of prairie dogs are known from the fossil record from the Late Blancan through the Holocene.

"Prairie dog" is a misnomer, as Cynomys is actually a ground squirrel. Squirrels are interesting in that their skulls are highly conserved, having changed little since the oldest-known squirrel (Protosciurus) appeared in the late Oligocene. This can be easily seen by comparing Cynomys to Spermophilus columbianus, the Columbian ground squirrel, S. variegatus, the rock squirrel, and Sciurus niger, the eastern fox squirrel. For this reason, one could call squirrels 'living fossils'.

To date, the lack of significant variation between squirrel species has frustrated efforts to discover their phylogenetic relationships. However, molecular studies suggest that the black-tailed and white-tailed prairie dogs form distinct clades, with the closet living relatives of all prairie dogs probably being the ground squirrels (Spermophilus).

This specimen, a male collected in Wind Cave National Park, Custer County, South Dakota, was made available to the University of Texas High-Resolution X-ray CT Facility for scanning courtesy of Dr. Donald Swiderski of the University of Michigan Museum of Zoology. Funding for scanning was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Timothy Rowe of The University of Texas at Austin.

The specimen was scanned by Matthew Colbert and Richard Ketcham on 27 July 2000 along the coronal axis for a total of 386 slices, each slice 0.16 mm thick, with an interslice spacing of 0.16 mm.

Goodwin, H. T. 1995. Systematic revision of fossil prairie dogs with descriptions of two new species. University of Kansas Museum of Natural History Miscellaneous Publication 86, 38 pp.

Goodwin, H. T. 1995. Pliocene-Pleistocene biogeographic history of prairie dogs, genus Cynomys (Sciuridae). Journal of Mammalogy 76:100-122.

Hoogland, J. L. 1996. Cynomys ludovicianus. Mammalian Species 535:1-10.

McCullough, D. A., R. K. Chesser, and R. D. Owen. 1987. Immunological systematics of prairie dogs. Journal of Mammalogy 68:561-568.

Pizzimenti, J. J. 1975. Evolution of the prairie dog genus Cynomys. Occasional papers of the Museum of Natural History, The University of Kansas 39:1-73.

Links

Mammalian Species account of Cynomys ludovicianus (American Society of Mammalogists)

Cynomys ludovicianus on The Animal Diversity Web (The University of Michigan Museum of Zoology)

Cynomys ludovicianus on The Mammals of Texas Online Edition

None available.