Ben Creisler
Some recent papers with free pdf links:
Free pdf:
Andrew R. C. Milner, Randall B. Irmis, Martin G. Lockley, Hendrik Klein, David L. Slauf and Anthony Romilio (2021)
First report of "Chirotherium" lulli from the Upper Triassic Chinle Formation of San Juan County, Utah.
In: Lucas, S. G., Hunt, A. P. & Lichtig, A. J., 2021, Fossil Record 7. New Mexico Museum of Natural History and Science Bulletin 82: 275â284Â
Free pdf:
We report the first occurrence of the track type "Chirotherium" lulli from western North America. Three specimens were discovered at the "Feather Ridge Tracksite" in the Owl Rock Member of the Chinle Formation within Bears Ears National Monument of San Juan County, Utah. The ichnospecies occurs in association with Grallator isp., Brachychirotherium parvum, and Rhynchosauroides isp., which are all common ichnotaxa in the upper part of the formation and across Pangea. By contrast, "C." lulli is a rare ichnotaxon globally and is presently only known from North America. The trackmaker is inferred to be a crocodile-line archosaur (pseudosuchian). The report increases the ichnotaxonomic diversity of the Chinle Formation to at least 14 ichnotaxa, which is one of the highest known from any Mesozoic formation in North America.
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Free pdf:
Martin Lockley, Hendrik Klein, Julia B. McHugh and Anthony Romilio (2021)
Fruita's first fossil footprint exhibit: the discovery of forgotten specimens in an historic former museum building.
In: Lucas, S. G., Hunt, A. P. & Lichtig, A. J., 2021, Fossil Record 7. New Mexico Museum of Natural History and Science Bulletin 82: 219-226Â
Free pdf:
As part of a 1930s public works project, two specimens revealing a total of ~20 tracks, preserved as natural casts, were collected and built into the interior walls of what was then the Fruita Museum in western Colorado. Based on our knowledge of the regional tetrapod ichnofaunas we are able to designate these as a "Triassic specimen" and a "Jurassic specimen" which invite description in detail. Although the geographical origin of both track assemblages is unknown, the tracks are well preserved, in partial trackways and can be identified with some confidence. Thus, one specimen is shown to reveal the ichnogenus Procolophonichnium and an indeterminate, probable therapsid track which marks the specimen as almost certainly from the Lower-Middle Triassic Moenkopi Formation. The other specimen reveals tridactyl tracks here identified as Anomoepus with associated traces which suggest it originated from the Upper Jurassic Morrison Formation.
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Free pdf:
Matthieu Moreau, Christopher J. Duffin, Claudia Hildebrandt, Deborah Hutchinson, Adam Parker, Simon Carpenter & Michael J. Benton (2021)
Microvertebrates from the Rhaetian basal bone bed of Saltford, near Bath, SW England.
Proceedings of the Geologists' Association (advance online publication)
doi:
https://doi.org/10.1016/j.pgeola.2020.11.003https://www.sciencedirect.com/science/article/abs/pii/S0016787820301188Free pdf:
https://cpb-eu-w2.wpmucdn.com/blogs.bristol.ac.uk/dist/6/525/files/2021/01/2021Saltford.pdfThe famous Rhaetian bone bed (Late Triassic, 205 Ma) is well known because it marks a major switch in depositional environment from terrestrial red beds to fully marine conditions throughout the UK and much of Europe. The bone bed is generally cemented and less than 10âcm thick. However, we report here an unusual case from Saltford, near Bath, S.W. England where the bone bed is unconsolidated and up to nearly 1âm thick. The exposure of the basal beds of the Westbury Formation, Penarth Group includes a bone bed containing a diverse Rhaetian marine microvertebrate fauna dominated by sharks, actinopterygian fishes and reptiles. Despite the unusual sedimentary character of the bone bed, we find similar proportions of taxa as in other basal Rhaetian bone beds (55â59 % Lissodus teeth, 13â16 % Rhomphaiodon teeth, 12â14 % Severnichthys teeth, 6â9% Gyrolepis teeth, 3â4% undetermined sharksâ teeth, 1â3% undetermined bony fish teeth, and < 1% of each of Hybodus, Parascylloides, and Sargodon), the only differences being in the proportions of Rhomphaiodon teeth, which can represent 30â40 % of specimens elsewhere. This suggests that taphonomic bias of varying Rhaetian bone beds may be comparable despite different sedimentary settings, and that the proportions of taxa say something about their original proportions in the ecosystem.