Project 3298: S. J. Nesbitt, R. K. Denton, M. A. Loewen, S. L. Brusatte, N. D. Smith, A. H. Turner, J. I. Kirkland, A. T. McDonald, D. G. Wolfe. 2019. A mid-Cretaceous tyrannosauroid and the origin of North American end-Cretaceous dinosaur assemblages. Nature Ecology & Evolution. 3 (6):892-899.
Specimen: † Suskityrannus hazelae (MSM:P6178)
View: cross section

Abstract

Late Cretaceous dinosaur assemblages of North America—characterized by gigantic tyrannosaurid predators, and large-bodied herbivorous ceratopsids and hadrosaurids—were highly successful from around 80 million years ago (Ma) until the end of the ‘Age of Dinosaurs’ 66 Ma. However, the origin of these iconic faunas remains poorly understood because of a large, global sampling gap in the mid-Cretaceous, associated with an extreme sea-level rise. We describe the most complete skeleton of a predatory dinosaur from this gap, which belongs to a new tyrannosauroid theropod from the Middle Turonian (~92 Ma) of southern Laramidia (western North America). This taxon, Suskityrannus hazelae gen. et sp. nov., is a small-bodied species phylogenetically intermediate between the oldest, smallest tyrannosauroids and the gigantic, last-surviving tyrannosaurids. The species already possesses many key features of the tyrannosaurid bauplan, including the phylogenetically earliest record of an arctometatarsalian foot in tyrannosauroids, indicating that the group developed enhanced cursorial abilities at small body size. Suskityrannus is part of a transitional Moreno Hill (that is, Zuni) dinosaur assemblage that includes dinosaur groups that became rare or were completely absent in North America around the final 15 Myr of the North American Cretaceous before the end-Cretaceous mass extinction, as well as small-bodied forebears of the large-bodied clades that dominated at this time.


Read the article »

Article DOI: 10.1038/s41559-019-0888-0

Project DOI: 10.7934/P3298, http://dx.doi.org/10.7934/P3298
This project contains
  • 2 Media
  • 3 Documents
  • 1 Taxon
  • 1 Specimen
Total size of project's media files: 1648 MB

Download Project SDD File
Currently Viewing:
MorphoBank Project 3298


    Members

    member name taxa specimens media
    Sterling Nesbitt
    Project Administrator
    Last logged in 05/06/19
    112


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views532
    Project overview199
    Media views160Media search (124 views); M669115 (17 views); M595506 (19 views);
    Taxon list39
    Views for media list37
    Bibliography21
    Specimen list55
    Documents list21




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project20
    Project downloads17
    Media downloads3M595506 (2 downloads); M669115 (1 download);