Project 946: M. J. Orliac, M. A. O'Leary. 2014. Comparative anatomy of the petrosal bone of dichobunoids, early members of Artiodactylamorpha (Mammalia). Journal of Mammalian Evolution. 21 (1).
Specimen: † Homacodon vagans Marsh, 1872 (USNM:482369)

Abstract

Among Artiodactylamorpha, dichobunoids are some of the oldest fossil species that have been associated with Artiodactyla, the crown clade that includes hippopotamids, camelids, suoids, ruminants and cetaceans. These important fossil species are known from Early Eocene rocks of North America, Europe and Asia but their phylogenetic position has yet to be well-resolved. Before generating such a phylogeny it is first critical to document all of the anatomy of known dichobunoid fossils. Here we use CT scans to describe previously unseen anatomy of the petrosal bone, a complex part of the mammalian skull that contains many variable and phylogenetically informative features. Results show that these extinct species share a number of features that are not documented in modern species including a lateral process of the epitympanic wing constituting the medial border of the piriform fenestra, and a tegmen tympani foramen that may have given passage to the ramus superior of the stapedial artery. Future comprehensive phylogenetic studies may show that many of these characters are plesiomophic for Artiodactylamopha. Some species (Diacodexis, Homacodon and ?Helohyus) exhibit a dorsolateral exposure of the mastoid region of the petrosal on the temporal part of the cranium. This uncommon feature has, to our knowledge, not been reported in another euungulate group.


Read the article »

Project DOI: 10.7934/P946, http://dx.doi.org/10.7934/P946
This project contains
  • 16 Media
  • 8 Taxa
  • 9 Specimens
Total size of project's media files: 10.04M

Download Project SDD File
Currently Viewing:
MorphoBank Project 946

    This research
    supported by

    Authors' Institutions

    • Universite de Montpellier

    • American Museum of Natural History

    • Stony Brook University



    Members

    member name taxa specimens media
    Maeva Orliac
    Project Administrator
    8813
    MorphoBank Curator
    Full membership
    000
    Maureen O'Leary
    Full membership
    013


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views46798
    Project overview4552
    Taxon list6429
    Specimen list9441
    Media views18996Media search (5824 views); M287488 (828 views); M287462 (836 views); M326180 (822 views); M307957 (1011 views); M287754 (844 views); M287463 (904 views); M287464 (815 views); M287486 (796 views); M287487 (796 views); M287489 (817 views); M287490 (787 views); M287491 (774 views); M287606 (741 views); M287607 (864 views); M287608 (736 views); M287609 (801 views);
    Bibliography1163
    Views for media list6210
    Documents list7




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project338
    Project downloads335
    Media downloads3M287486 (2 downloads); M287464 (1 download);