• Login
    View Item 
    •   Treasures Home
    • Academic Schools and Programs
    • School of Natural Sciences and Mathematics
    • NSM Faculty Research
    • Geissman, John W.
    • View Item
    •   Treasures Home
    • Academic Schools and Programs
    • School of Natural Sciences and Mathematics
    • NSM Faculty Research
    • Geissman, John W.
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Paleontology of the Blaauwater 67 and 65 Farms, South Africa: Testing the Daptocephalus/Lystrosaurus Biozone Boundary in a Stratigraphic Framework

    Thumbnail
    View/Open
    Link (88.86Kb)
    Date
    2017-06
    Author
    Gastaldo, Roberta
    Neveling, Johann
    Looy, Cindy V.
    Bamford, Marion K.
    Kamo, Sandra L.
    Geissman, John W.
    Metadata
    Show full item record
    Abstract
    Abstract
    Vertebrate paleontologists have proposed a model for the terrestrial end-Permian event in the Karoo Basin, South Africa. The scenario envisions vegetational collapse that resulted in a phased extinction of vertebrate taxa in the uppermost Daptocephalus Assemblage Zone and overlying Lystrosaurus Assemblage Zone. These biodiversity patterns are placed into composite stratigraphic sections at key localities, several of which are in close spatial proximity. We present a stratigraphic framework at two of these localities, Old Lootsberg Pass and Tweefontein, physically correlated over similar to 2 km distance into which new and previously reported fossils are placed. Glossopterid-dominated megafloras occur in both the Daptocephalus and Lystrosaurus biozones, along with palynological assemblages. Katbergia, a burrow used by others as an indicator of the transition and post-transition interval, occurs in paleosols much lower in the upper Daptocephalus Assemblage Zone, along with various subhorizontal cylindrical structures interpreted as vertebrate burrows. New vertebrate specimens include: (1) a large skull of either Daptocephalus leoniceps or Dicynodon sp.; (2) a partial skull with large canine assignable to either Dicynodon, Daptocephalus, or Lystrosaurus mccaigi; (3) a Lystrosaurus canine in grayish-red siltstone; (4) a skull of Lystrosaurus murrayi; and (5) a non-diagnostic post-cranial skeleton of lystrosaurid affinity. These fossils are combined with the published Karoo-vertebrate dataset to test the stratigraphic position of the Daptocephalus and Lystrosaurus Assemblage Zone boundary. We conclude that: (1) glossopterids in the Lystrosaurus Assemblage Zone indicate persistence of the clade past what is considered to be an extinction event; (2) the presence of palynomorphs known from recovery clades above the proposed vertebrate-biozone boundary indicate that these groups were present in the basin, but outside of the megafloral taphonomic window; (3) the position of the proposed vertebrate assemblage-zone boundary is stratigraphically inconsistent and varies in its reported stratigraphic position at a minimum of 25 m, and up to 70 m, across a distance of only similar to 2 km; and (4) terrestrial ecosystem dynamics only can be assessed when a high resolution stratigraphic framework is developed into which biostratigraphic data are placed and, thereafter, patterns can be evaluated.
    URI
    http://hdl.handle.net/10735.1/6006
    Collections
    • Geissman, John W.

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of TreasuresCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Login

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV