Theropod specimens from the Navesink Formation and their implications for the Diversity and Biogeography of Ornithomimosaurs and Tyrannosauroids on Appalachia
- Published
- Accepted
- Subject Areas
- Biogeography, Ecology, Paleontology, Taxonomy
- Keywords
- Appalachia, Cretaceous, Tyrannosaurs, Ornithomimosaurs
- Copyright
- © 2017 Brownstein
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Theropod specimens from the Navesink Formation and their implications for the Diversity and Biogeography of Ornithomimosaurs and Tyrannosauroids on Appalachia. PeerJ Preprints 5:e3105v1 https://doi.org/10.7287/peerj.preprints.3105v1
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 Appalachiosaurus montgomeriensis, both which are only known from partial skeletons with few overlapping elements. Recently, the generic name Teihivenator was given to another tyrannosaur named “Laelaps” macropus by Cope (1868) by Yun (2017). However, examination of the specimens by the author show morphologies at odds with the morphological descriptions given by Yun (2017). The tyrannosaur named by Yun (2017), known from partial lower hindlimb elements including the portions of two metatarsals and a partial tibia, is shown herein to be a chimaera of ornithomimosaur and tyrannosauroid hindlimb elements. The several different dinosaur specimens which compose the syntypes of “Teihivenator” include three ornithomimosaur pedal phalanges with affinities to derived ornithomimid taxa, a proximal end of the right metatarsal II and a distal end of the right metatarsal II from either ornithomimosaurs or tyrannosauroids, and a partial tibia of a tyrannosauroid distinct from Dryptosaurus or Appalachiosaurus but nevertheless considered here to be from an indeterminate taxon based on the lack of observable autopomorphies and issues with the comparability of the specimen to other taxa. The specimens are nevertheless important for revealing further the theropod fauna of the Maastrichtian Navesink Formation of New Jersey, as well as for possibly increasing the diversity of tyrannosauroids and further illuminating the presence of ornithomimosaurs on Appalachia.
Author Comment
This is a preprint submission to PeerJ Preprints.