Neurosensory and Sinus Evolution as Tyrannosauroid Dinosaurs Developed Giant Size: Insight from the Endocranial Anatomy of Bistahieversor sealeyi.

Autor: McKeown M; School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK., Brusatte SL; School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK., Williamson TE; New Mexico Museum of Natural History and Science, Albuquerque, New Mexico., Schwab JA; School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK., Carr TD; Department of Biology, Carthage College, Kenosha, Wisconsin., Butler IB; School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK., Muir A; School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK., Schroeder K; New Mexico Museum of Natural History and Science, Albuquerque, New Mexico., Espy MA; Los Alamos National Laboratory, Los Alamos, New Mexico., Hunter JF; Los Alamos National Laboratory, Los Alamos, New Mexico., Losko AS; Los Alamos National Laboratory, Los Alamos, New Mexico.; Research Neutron Source FRM II, Technical University Munich, Munich, Germany., Nelson RO; Los Alamos National Laboratory, Los Alamos, New Mexico., Gautier DC; Los Alamos National Laboratory, Los Alamos, New Mexico., Vogel SC; Los Alamos National Laboratory, Los Alamos, New Mexico.
Jazyk: angličtina
Zdroj: Anatomical record (Hoboken, N.J. : 2007) [Anat Rec (Hoboken)] 2020 Apr; Vol. 303 (4), pp. 1043-1059. Date of Electronic Publication: 2020 Jan 22.
DOI: 10.1002/ar.24374
Abstrakt: Tyrannosaurus rex and other tyrannosaurid dinosaurs were apex predators during the latest Cretaceous, which combined giant size and advanced neurosensory systems. Computed tomography (CT) data have shown that tyrannosaurids had a trademark system of a large brain, large olfactory bulbs, elongate cochlear ducts, and expansive endocranial sinuses surrounding the brain and sense organs. Older, smaller tyrannosauroid relatives of tyrannosaurids developed some, but not all, of these features, raising the hypothesis that tyrannosaurid-style brains evolved before the enlarged tyrannosaurid-style sinuses, which might have developed only with large body size. This has been difficult to test, however, because little is known about the brains and sinuses of the first large-bodied tyrannosauroids, which evolved prior to Tyrannosauridae. We here present the first CT data for one of these species, Bistahieversor sealeyi from New Mexico. Bistahieversor had a nearly identical brain and sinus system as tyrannosaurids like Tyrannosaurus, including a large brain, large olfactory bulbs, reduced cerebral hemispheres, and optic lobes, a small tab-like flocculus, long and straight cochlear ducts, and voluminous sinuses that include a supraocciptal recess, subcondyar sinus, and an anterior tympanic recess that exits the braincase via a prootic fossa. When characters are plotted onto tyrannosauroid phylogeny, there is a two-stage sequence in which features of the tyrannosaurid-style brain evolved first (in smaller, nontyrannosaurid species like Timurlengia), followed by features of the tyrannosaurid-style sinuses (in the first large-bodied nontyrannosaurid tyrannosauroids like Bistahieversor). This suggests that the signature tyrannosaurid sinus system evolved in concert with large size, whereas the brain did not. Anat Rec, 303:1043-1059, 2020. © 2020 American Association for Anatomy.
(© 2020 American Association for Anatomy.)
Databáze: MEDLINE
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