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 views40123
    Project overview4182
    Taxon list5625
    Specimen list7927
    Media views16167Media search (5130 views); M287488 (691 views); M287462 (715 views); M326180 (697 views); M307957 (858 views); M287754 (700 views); M287463 (765 views); M287464 (680 views); M287486 (664 views); M287487 (664 views); M287489 (686 views); M287490 (650 views); M287491 (639 views); M287606 (619 views); M287607 (733 views); M287608 (606 views); M287609 (670 views);
    Bibliography982
    Views for media list5240




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project291
    Project downloads288
    Media downloads3M287486 (2 downloads); M287464 (1 download);