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Article
Resurrection and Redescription of the Pocket Gopher Thomomys sheldoni from the Sierra Madre Occidental of Mexico
Journal of Mammalogy (2013)
  • Verity L. Mathis, Louisiana State University
  • Mark S. Hafner, Louisiana State University
  • David J. Hafner, University of New Mexico
  • James W. Demastes, University of Northern Iowa
Abstract
Thomomys sheldoni Bailey, 1915 is resurrected to recognize a genetically divergent clade of smooth-toothed pocket gophers that inhabits the high-elevation pine-oak forests of the Sierra Madre Occidental in Mexico from northwestern Chihuahua through Durango to western Zacatecas and northeastern Nayarit. Analyses of DNA sequences from 8 genes and genotype assignment tests for 21 allozyme loci establish this clade as a genetically isolated taxon within the T. umbrinus (sensu lato) complex. In addition to the T. sheldoni clade (diploid number of 2n = 76), 3 genetic clades within T. umbrinus (2n = 78) and 1 newly discovered clade (2n = 76) also were recovered in the phylogenetic analyses. Individuals of T. sheldoni and T. umbrinus occur in close proximity with no evidence of gene flow and an average cytochrome-b genetic divergence of 15.6%. Analyses of cranial morphology reveal that skulls ofT. sheldoni are, on average, broader and longer than skulls of T. umbrinus and T. atrovarius. We recognize and provide synonymies for 2 subspecies within T. sheldoni based on a weak genetic and morphological break that is coincident with a large, north-south gap in its distribution: T. s. sheldoni in the southern Sierra Madre Occidental, which includes specimens from the type locality and populations in Durango, Zacatecas, and Nayarit; and T. s. chihuahuae in the northern Sierra Madre Occidental, which is known only from Chihuahua.
Keywords
  • allozymes,
  • cytochrome b,
  • DNA sequences,
  • genetic differentiation,
  • Geomyidae,
  • phylogenetics,
  • Rodentia
Disciplines
Publication Date
2013
DOI
http://dx.doi.org/10.1644/12-MAMM-A-225.1
Citation Information
Verity L. Mathis, Mark S. Hafner, David J. Hafner and James W. Demastes. "Resurrection and Redescription of the Pocket Gopher Thomomys sheldoni from the Sierra Madre Occidental of Mexico" Journal of Mammalogy Vol. 94 Iss. 3 (2013) p. 544 - 560
Available at: http://works.bepress.com/james_demastes/5/