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 (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: 12 MB

Download Project SDD File
Currently Viewing:
MorphoBank Project 946

    This research
    supported by



    Members

    member name taxa specimens media
    Maeva Orliac
    Project Administrator
    Last logged in 02/14/14
    8813
    MorphoBank Curator
    Full membership
    Last logged in 08/06/14
    000
    Maureen O'Leary
    Full membership
    Last logged in 02/05/14
    013


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views28907
    Project overview3354
    Taxon list3574
    Specimen list5544
    Media views12006Media search (3925 views); M287488 (505 views); M287462 (526 views); M326180 (518 views); M307957 (667 views); M287754 (509 views); M287463 (584 views); M287464 (496 views); M287486 (480 views); M287487 (485 views); M287489 (505 views); M287490 (471 views); M287491 (453 views); M287606 (442 views); M287607 (554 views); M287608 (417 views); M287609 (469 views);
    Bibliography729
    Views for media list3700




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project177
    Project downloads174
    Media downloads3M287486 (2 downloads); M287464 (1 download);