Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology

• 成果类型: Article
• 署名作者: Cullen, Thomas M.; Larson, Derek W.; Witton, Mark P.; Scott, Diane; Maho, Tea; Brink, Kirstin S.; Evans, David C.; Reisz, Robert
• 署名单位: Auburn University System; Auburn University; University of Ottawa; Carleton University; Field Museum of Natural History (Chicago); University of Toronto; University of Portsmouth; Jilin University; Jilin University; University of Toronto; University Toronto Mississauga; University of Manitoba; Royal Ontario Museum
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10076
• DOI: 10.1126/science.abo7877
• 发表日期: 2023-03-31
• 页码: 1348-1351
• 关键词: alligators; EVOLUTION; teeth

摘要

Large theropod dinosaurs are often reconstructed with their marginal dentition exposed because of the enormous size of their teeth and their phylogenetic association to crocodylians. We tested this hypothesis using a multiproxy approach. Regressions of skull length and tooth size for a range of theropods and extant varanid lizards confirm that complete coverage of theropod dinosaur teeth with extraoral tissues (gingiva and labial scales) is both plausible and consistent with patterns observed in living ziphodont amniotes. Analyses of dental histology from crocodylians and theropod dinosaurs, including Tyrannosaurus rex, further indicate that the most likely condition was complete coverage of the marginal dentition with extraoral tissue when the mouth was closed. This changes our perceptions about the appearance and oral configuration of these iconic predators and has broad implications for our interpretations of other terrestrial animals with large teeth.