Thursday, May 22, 2014

Faunal update

I've heard in regard to blogging that "Never has so much been written by so many that will be read by so few", and seeing as it's not dissertation or family related it has been a while since I updated this blog. However, I've given a few talks at conferences the past month detailing new Wayan/Idaho Cretaceous discoveries, so it's a good time to share this new information here.

My talks this spring were at the Mid-Mesozoic conference in Utah and Colorado (http://www.utahpaleo.org/mid-mesozoic-conference.html), and the regional GSA meetings here in Bozman (https://gsa.confex.com/gsa/2014RM/webprogram/Paper238289.html). The former talk outlined Wayan fauna and taphonomy, and the latter the fauna and taphonomy of the bonebed found last year that I have termed the Robison Bonebed, after my friend and mentor Steve Robison. Between the Robison bonebed, another site yet to be discussed, and other Wayan localities we are just starting to finally get real diversity (albeit very fragmentary fossils) for the Wayan fauna. So here is an updated listing of all the critters we now know about:
  • Oryctodromeus: A small burrowing ornithopod. This animal heavily dominates the Wayan fossil assemblage, >12 partial to near complete skeletons and lots of isolated bits and pieces.
  • Hadrosaur: Known from a tooth from the Robison Bonebed. These large ornithopods were fairly new arrivals on the Cretaceous scene at this time and would be dominant in later Late Cretaceous faunas.
  • Iguanodont: Known from a few isolated teeth and bones from various localities.
  • Nodosaurs: Known from isolated teeth, a partial skeleton currently under research, and arguably common scutes, teeth, and vertebrae from the Robison Bonebed.
  • Giant oviraptorosaur: Represented by very common isolated eggshell, eggshell concentrations, and rare large eggs.
  • Tyrannosaurid: Known from isolated teeth. These are small animals that have not yet achieved the giant size that tyrannosaurs would gain in the later Late Cretaceous.
  • Cf. Neovenatorid allosauroid: This animal is represented by a small vertebra from a young animal.
  • Dromaeosaurs: Known from rare teeth from various localities.
  • Coelurosaurs/indeterminate small theropod(s): Known from teeth and bones from a few localities. I'm hoping to get better identifications on these and more material.
  • Large, maybe Allosaurus-sized, possible fish-eating theropod: This animal is known from teeth from the Robison Bonebed. The teeth are distinctive and I can't seem to find anything that matches them.
  • Triconodontid mammals: Known from isolated teeth from two localites.
  • Non-cimolodontan multituberculate mammal: Known from a jaw with teeth found at the Robison Bonebed.
  • Cimolodontan mammal: Known from teeth from one site.
  • Eutriconodontid mammal: Known from teeth from one site.
  • Metatherian mammal: Known from teeth from one site.
  • Indeterminate mammals: Known from teeth from the Robison Bonebed.
  • Deinosuchus-like/Large goniopholid crocodylian: Partial skull currently under research.
  • Small crocodylians: Known from teeth from a number of sites.
  • Turtles: Fairly common shell fragments from a number of sites.
  • Semionotid fish: Known from hundreds of large crushing teeth and a few scales from a few sites. The size of one scale indicates maybe close to a meter in length at least for some of these fish.
And here's a figure that generally summarizes the fauna of the Wayan, made in this case to represent the fauna from the bonebed.


Once work is completed on these sites and specimens a number of publications will come out on all these bits and pieces. Hopefully in the interim we can find some more complete material of all these animals.

A few useful references:


Dorr, J.A. 1985. Newfound Early Cretaceous Dinosaurs and Other Fossils in Southeastern Idaho and Westernmost Wyoming, Contributions from the Museum of Paleontology, University of Michigan 27(3):73- 85.  Link: http://deepblue.lib.umich.edu/bitstream/handle/2027.42/48524/ID377.pdf


Krumenacker, L. J.; 2010. Chronostratigraphy and paleontology of the mid-Cretaceous Wayan Formation   of eastern Idaho, with a description of the first Oryctodromeus specimens from Idaho (MS), Brigham Young University. Link: http://contentdm.lib.byu.edu/cdm/ref/collection/ETD/id/2317
 

Simon, J. D., D. J. Varricchio, F. D. Jackson, and S. R. Robison, 2012. Giant theropod eggs from the Albian-Cenomanian Wayan Formation of Idaho: Taxonomic, paleogeographic, and reproductive implications. Journal of Vertebrate Paleontology 32 (3, supplement):174.



2 comments:

  1. I love how it's obviously you as the human silhouette in the middle of your figure.

    ReplyDelete
  2. I'm impressed you picked that out. I really wanted to have them all in scale to Spock giving his salute.

    ReplyDelete