Current address: University of Washington, Department of Biology, 24 Kincaid Hall, Box 351800, Seattle, Washington 98195–1800, USA.
Intraspecific versus interspecific variation in Miocene Great Basin mylagaulids: implications for systematics and evolutionary history
Article first published online: 25 JAN 2012
© 2012 The Linnean Society of London
Zoological Journal of the Linnean Society
Volume 164, Issue 2, pages 427–450, February 2012
How to Cite
CALEDE, J. J. M. and HOPKINS, S. S. B. (2012), Intraspecific versus interspecific variation in Miocene Great Basin mylagaulids: implications for systematics and evolutionary history. Zoological Journal of the Linnean Society, 164: 427–450. doi: 10.1111/j.1096-3642.2011.00765.x
- Issue published online: 25 JAN 2012
- Article first published online: 25 JAN 2012
- Received 24 September 2010; revised 10 March 2011; accepted for publication 2 June 2011
- dental morphology;
- Thousand Creek;
- Virgin Valley
The Mylagaulidae are a family of burrowing rodents abundant in Miocene faunas from western North America. Recent taxonomic revisions of mylagaulids from the Great Plains suggest that their systematics may be best understood on a regional basis. Previous studies addressed the taxonomy and evolutionary history of mylagaulids from the Great Basin, but recent discoveries of specimens, new phylogenetic data, and more detailed stratigraphical information necessitate a thorough reanalysis of their relationships and occurrences. We present a revision of the systematics of the mylagaulids from the Great Basin. In addition to rare large mylagaulids of uncertain taxonomic affinity, we recognize four species of mylagaulids distributed throughout Oregon and Nevada from the late Hemingfordian through to the early late Hemphillian: Alphagaulus vetus, Hesperogaulus gazini, Hesperogaulus wilsoni, and a new species from the genus Hesperogaulus. All species are known from large sample sizes of isolated premolars, allowing consideration of ontogenetic variation in determining the key morphological differences that allow recognition of different species. Although the number of enamel lakes varies within a given taxon, the presence of some of these lakes is taxonomically significant. This result emphasizes the importance of understanding ontogeny in describing species of fossil hypsodont mammals.
© 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164, 427–450.