Theropod specimens from the Navesink Formation and their implications for the Diversity and Biogeography of Ornithomimosaurs and Tyrannosauroids on Appalachia

Abstract

The sparse dinosaur record of eastern North America has rendered the dinosaurs of the Late Cretaceous landmass of Appalachia obscure. This landmass, isolated from the western landmass Laramidia by a great inland sea known as the Western Interior Seaway, may have been a safe haven for dinosaur species which would be replaced on Appalachia's western contemporary. An excellent example of these isolated forms are the tyrannosaurs of Appalachia, which have not only been grouped outside Tyrannosauridae proper in phylogenetic analyses, but also bare distinct morphologies, including a gigantic manus in one form, from these 'western tyrants'. However, Appalachian tyrannosaurs are only represented currently by the two valid taxa Dryptosaurus aquilunguis and Introduction.

Theropod specimens from the Navesink Formation and their implications for the Diversity and Biogeography of Ornithomimosaurs and Tyrannosauroids on Appalachia

“…obs. ) and the the temporally equivalent and geographically adjacent faunas of the Tar Heel and Coachman Formations (fauna includes Dryptosaurus aquilunguis and Appalachiosaurus montgomeriensis)(e.g., Baird & Horner, 1979;Weishampel & Young, 1996;Schwimmer et al, 2015). The presence of two tyrannosauroids in the same ecosystem is also known in a few units from Laramidia (e.g., Weishampel et al, 2004).…”

“…Appalachiosaurus is also known from multiple other Campanian units in the southeastern United States (e.g., Ebersole & King, 2011). Recently, Schwimmer et al (2015) described teeth and bones of Appalachiosaurus montgomeriensis from eastern South Carolina. Remains from the Missouri Chronister Site have also been assigned to an undetermined genus of tyrannosaur (Fix & Darrough, 2004).…”