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Theropod teeth from Hell Creek Formation “Sue” Quarry

From: Ben Creisler

A new online paper:

Terry A. Gates, Lindsay E. Zanno, and Peter J. Makovicky (2013)
Theropod teeth from the upper Maastrichtian Hell Creek Formation “Sue”
Quarry: New morphotypes and faunal comparisons.
Acta Palaeontologica Polonica (in press)
doi: http://dx.doi.org/10.4202/app.2012.0145

Isolated teeth from vertebrate microfossil localities often provide
unique information on the biodiversity of ancient ecosystems that
might otherwise remain unrecognized. Microfossil sampling is a
particularly valuable tool for documenting taxa that are poorly
represented in macrofossil surveys due to small body size, fragile
skeletal structure, or relatively low ecosystem abundance. Because
biodiversity patterns in the late Maastrichtian of North American are
the primary data for a broad array of studies regarding non-avian
dinosaur extinction in the terminal Cretaceous, intensive sampling on
multiple scales is critical to understanding the nature of this event.
We address theropod biodiversity in the Maastrichtian by examining
teeth collected from the Hell Creek Formation locality that yielded
FMNH PR 2081 (the Tyrannosaurus rex specimen “Sue”). Eight morphotypes
(three previously undocumented) are identified in the sample,
representing Tyrannosauridae, Dromaeosauridae, Troodontidae, and
Avialae. Noticeably absent are teeth attributed to the morphotypes
Richardoestesia and Paronychodon. Morphometric comparison to
dromaeosaurid teeth from multiple Hell Creek and Lance Formation
microsites reveals two unique dromaeosaurid morphotypes bearing finer
distal denticles than present on teeth of similar size, and also
differences in crown shape in at least one of these. These findings
suggest more dromaeosaurid taxa, and a higher Maastrichtian
biodiversity, than previously appreciated.