Biogeography of terrestrial and freshwater vertebrates from the late Cretaceous (Campanian) Western Interior of North America

Neovenatorid theropods are apex predators in the Late Cretaceous of North America

“…O ver a century of collection efforts have rendered Late Jurassic and latest Cretaceous (Campano-Maastrichtian) terrestrial ecosystems in western North America among most densely sampled and comprehensively understood dinosaur faunas in the world [1][2][3] . These distinct windows into North American dinosaur evolution stand in marked contrast to each other in taxonomic content, degree of endemism and body mass composition, and together bracket a dramatic faunal reorganization of apex predatory guilds on the continent 4 .…”

The biogeography and ecology of the Cretaceous non-avian dinosaurs of Appalachia

“…Campanian Appalachian faunas were compared to those of the Wahweap, Kaiparowits, and Kirtland formations representing southern Campanian Laramidian faunas and with the Oldman, Dinosaur Park, and Judith River formations representing northern Campanian Laramidian faunas, whereas the Maastrichtian Appalachian faunas were compared with those of the Javelina, Hell Creek, Lance, and Horseshoe Canyon formations. The Laramidian (western North American) faunas used for comparisons are among the most well known (e.g., Kirkland et al, 1998;, Weishampel, 2006Gates et al, 2010;Zanno and Makovicky, 2013;Farke et al, 2014) and represent a sampling of northern, middle, and southern faunas, both factors being considered to minimize statistical bias and error on the part of such faunas. As such, formations like the Foremost Formation, from which only a few taxa and indeterminate elements are known (e.g., Weishampel et al, 2004), were not included.…”

“…Indeterminate specimens assignable to the "family level", even those which were the only representation of the presence of a particular clade in a faunas, were only included in "family 4 level" calculations. This protocol was used in order to make the analyses herein more comparable to those of Gates et al (2010), who coded their datasets at the "family", genus, and genus-species levels. The latter level was not used in analyses herein, as so few Appalachian dinosaur fossils are identifiable past the genus level (see Appendix 1 and the Review section).…”

“…Biases. As previous studies have noted, biases in the collection of fossils, use of previously published literature, taphonomic biases among and within sedimentary units, and temporal differences among sedimentary units studied and within their faunas all play a role in skewing paleobiogeographic analyses (e.g., Nicholls and Russell, 1990;Lehman, 1997;Gates et al, 2010). Because of these factors, the specific paleoenvironments, taphonomy, and age of sediments compared herein were extensively reviewed and compared in the Results section.…”

The definition of sexual selection and its implications for dinosaurian biology

“…This pattern is indeed not what we originally predicted for dinosaurs (although this does not negate our hypothesis as a general prediction). However, it may speak to regional biogeographic patterns in ways that we did not originally consider, if (for example) the latest Cretaceous Triceratops lineage in Montana diverged at some point from common ancestors with its sister lineage in the basins of Utah and New Mexico (Gates et al, 2010), if in fact they are distinct lineages in these regions.…”