2025-12-04 イェール大学
An artist’s rendering of Nanotyrannus lancensis (foreground), a species of small dinosaurs that lived contemporaneously with the much larger Tyrannosaurus rex.Illustration by Andrey Atuchin, courtesy of Cleveland Museum of Natural History
＜関連情報＞
- https://news.yale.edu/2025/12/04/teen-rex-no-more-new-study-agrees-nanotyrannus-separate-species
- https://www.science.org/doi/10.1126/science.adx8706
小型のティラノサウルスがティラノサウルス・レックスと並んで生息していた A diminutive tyrannosaur lived alongside Tyrannosaurus rex
Christopher T. Griffin, Jeb Bugos, Ashley W. Poust, Zachary S. Morris, […] , and Caitlin Colleary
Science Published:4 Dec 2025
DOI:https://doi.org/10.1126/science.adx8706
Abstract
Whether Nanotyrannus lancensis represents a distinct taxon or an immature Tyrannosaurus rex is a decades-long controversy. The N. lancesis holotype is an isolated skull and ceratobranchials, but limb osteohistology of Nanotyrannus-like individuals implies that these individuals were immature Tyrannosaurus, suggesting that the Nanotyrannus holotype is also immature. We demonstrate that ceratobranchial (‘hyoid’) histology is useful for ontogenetic assessment in extant and extinct archosaurs. The ceratobranchial histology of the N. lancensis holotype indicates that it was nearing or had reached skeletal maturity, suggesting that it is taxonomically distinct from the coeval Tyrannosaurus rex and that Hell Creek (and equivalent) ecosystems supported a diverse assemblage of predatory dinosaurs approaching the K-Pg extinction.
