Get access

Micro-computed tomography reveals a diversity of Peramuran mammals from the Purbeck Group (Berriasian) of England

Authors

  • BRIAN M. DAVIS

    1. Department of Zoology and the Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, OK 73072, USA; e-mail: Davis-B@mssu.edu
    2. Current address: Department of Biology and Environmental Health, Missouri Southern State University, Joplin, MO 64801, USA
    Search for more papers by this author

Abstract

Abstract:  The known sample of the important pretribosphenic mammal Peramus tenuirostris, housed in the Natural History Museum (London, UK), was imaged using micro-computed tomography (CT). Substantial morphological diversity was discovered, prompting establishment (and resurrection) of additional taxa from within the existing hypodigm of Peramus tenuirostris: Peramus dubius comb. nov., Kouriogenys minor gen. nov. and Peramuroides tenuiscus gen. et sp. nov. The Peramura are revised; this group is restricted to taxa with clear evidence of a fully functional upper molar embrasure for the dominant lower molar talonid cusp (hypoconid), either through development of wear facet 4 or through differentiation of a distinct hypoconulid. The Peramura are the most likely sister taxon to the Tribosphenida (including living marsupials and placentals) and represent a distinct molar morphotype, transitional between primitive lineages characterized by dominant orthal shear (e.g. dryolestoids) and those with modern, multi-functional tribospheny. A very large masseteric foramen is identified in peramurans, but this feature appears to be autapomorphic and of uncertain function.

Get access to the full text of this article

Ancillary