A new tyrannosaurine (Theropoda:Tyrannosauridae) from the Campanian Foremost Formation of Alberta, Canada, provides insight into the evolution and biogeography of tyrannosaurids
Date
2020-01-23
Journal Title
Journal ISSN
Volume Title
Publisher
Cretaceous Research (Elsevier)
Abstract
Upper Cretaceous tyrannosauroid material from North America was primarily known from upper
Campanian through Maastrichtian formations until the recent discovery of derived tyrannosaurid taxa
from lower-to-mid Campanian deposits in the southwestern United States. However, diagnostic material
from contemporaneous deposits further north in Alberta (Canada) and Montana (USA) has yet to be
documented. Here we report the discovery of a new tyrannosaurine tyrannosaurid from the mid-
Campanian Foremost Formation of Alberta, Thanatotheristes degrootorum gen. et. sp. nov, which helps
fill this gap. The new tyrannosaurine, diagnosed by five autapomorphies, is found to be the sister taxon to
the late Campanian genus Daspletosaurus. Thanatotheristes is distinct from Daspletosaurus based on
several features, and lacks at least two apomorphies of the latter taxon. Together, these taxa form the
newly established Daspletosaurini, a clade of long-, deep-snouted tyrannosaurines endemic to northern
Laramidia during the Campanian. Our study demonstrates that Tyrannosauridae is composed of several
geographically-segregated clades rather than a series of monogeneric successive sister taxa as recovered
by previous studies. The geographic segregation of tyrannosaurid clades within North America provides
renewed evidence for provinciality among large theropods during the Late Cretaceous.
Description
Keywords
Theropoda, Tyrannosauridae, Campanian, Evolution, Provinciality, Biogeography
Citation
Voris, J. T., Therrien, F., Zelenitsky, D. K., & Brown, C. M. (2020). A new tyrannosaurine (Theropoda:Tyrannosauridae) from the Campanian Foremost Formation of Alberta, Canada, provides insight into the evolution and biogeography of tyrannosaurids. Cretaceous Research, 110, 104388. https://doi.org/10.1016/j.cretres.2020.104388