Taphonomy of a Lance Formation(Maastrichtian, WY) Dinosaur Bonebed with a Focus on Tooth Traces

<p>The Rose Quarry bonebed found in the Maastrichtian Lance Formation of eastern Wyoming possesses a complex blendof taphonomic signatures. Disarticulated, disassociated, fragmented bones of various states of abrasion from dinosaurs, turtles, and crocodilians are clustered together in a channelized sandstone unit. The mismatched taphonomic signatures of the bonebed suggest that it is amixed assemblage, containing bones with different taphonomic histories that were washed together by a flood event. Sedimentological data,includingthe presence of large mud clasts in the bonebed,agree well with this hypothesis. The abundant breakage of the bones in the Rose Quarry bonebed is attributed mainly to trampling. This study highlights the striking variability possible in fluvial bonebeds, including differences in pre-burial history, depositional mechanism, subenvironment, and post-burial history.</p> <p>Although only a few Rose Quarry bones show evidence of tooth traces, a similar nearby bonebed contained a tyrannosaurid metatarsal (HRS13997)that possessed numerous scores on the posterolateral surface near its ventral end. The presence of a <em>Knethichnus parallelum </em>tooth trace, the first known on a tyrannosaurid bone, allows for us to measure the widths of the striations left by the tooth denticles scraping along the bone’s surface. Comparison with theropod teeth from the Lance Formation leads us to concludeit was bitten by another tyrannosaurid, suggesting possible cannibalism in the species <em>Tyrannosaurus rex</em>.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Basic Sciences

Year

2016

Author dc:creator

• McLain, Matthew A.

Contributors dc:contributor

• Brand, Leonard R.
• Buchheim, H. Paul
• Chadwick, Arthur
• Dunbar, Stephen G.
• Nalin, Ronald
• Nick, Kevin E.

• Earth Sciences
• Paleontology
• Paleontology -- Wyoming; Taphonomy; Fossilization; Paleoecology; Sedimentary geology
• Lance Formation (Maastrichtian); Rose Quarry Bonebed; Fluvial bonebeds; Tooth traces; Post-burial history; Dinosaurs

Statement dc:rights

• This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Language dc:language

English

Repository record dc:identifier

https://scholarsrepository.llu.edu/etd/410

OAI identifier oai:identifier

oai:scholarsrepository.llu.edu:etd-1410