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Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis
Extensive oral processing of food through dental occlusion and orbital mandibular movement is often cited as a uniquely mammalian trait that contributed to their evolutionary success. Save for mandibular translation, these adaptations are not seen in extant archosaurs or lepidosaurs. In contrast, so...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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PeerJ Inc.
2016
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941762/ https://www.ncbi.nlm.nih.gov/pubmed/27441111 http://dx.doi.org/10.7717/peerj.2132 |
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author | Varriale, Frank J. |
author_facet | Varriale, Frank J. |
author_sort | Varriale, Frank J. |
collection | PubMed |
description | Extensive oral processing of food through dental occlusion and orbital mandibular movement is often cited as a uniquely mammalian trait that contributed to their evolutionary success. Save for mandibular translation, these adaptations are not seen in extant archosaurs or lepidosaurs. In contrast, some ornithischian dinosaurs show evidence of precise dental occlusion, habitual intraoral trituration and complex jaw motion. To date, however, a robust understanding of the diversity of jaw mechanics within non-avian dinosaurs, and its comparison with other vertebrates, remains unrealized. Large dental batteries, well-developed dental wear facets, and robust jaws suggests that neoceratopsian (horned) dinosaurs were capable chewers. But, biomechanical analyses have assumed a relatively simple, scissor-like (orthal) jaw mechanism for these animals. New analyses of dental microwear, presented here, show curvilinear striations on the teeth of Leptoceratops. These features indicate a rostral to caudal orbital motion of the mandible during chewing. A rostrocaudal mandibular orbit is seen in multituberculates, haramiyid allotherians, and some rodents, and its identification in Leptoceratops gracilis is the first evidence of complex, mammal-like chewing in a ceratopsian dinosaur. The term circumpalinal is here proposed to distinguish this new style of chewing from other models of ceratopsian mastication that also involve a palinal component. This previously unrecognized complexity in dinosaurian jaw mechanics indicates that some neoceratopsian dinosaurs achieved a mammalian level of masticatory efficiency through novel adaptive solutions. |
format | Online Article Text |
id | pubmed-4941762 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | PeerJ Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-49417622016-07-20 Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis Varriale, Frank J. PeerJ Evolutionary Studies Extensive oral processing of food through dental occlusion and orbital mandibular movement is often cited as a uniquely mammalian trait that contributed to their evolutionary success. Save for mandibular translation, these adaptations are not seen in extant archosaurs or lepidosaurs. In contrast, some ornithischian dinosaurs show evidence of precise dental occlusion, habitual intraoral trituration and complex jaw motion. To date, however, a robust understanding of the diversity of jaw mechanics within non-avian dinosaurs, and its comparison with other vertebrates, remains unrealized. Large dental batteries, well-developed dental wear facets, and robust jaws suggests that neoceratopsian (horned) dinosaurs were capable chewers. But, biomechanical analyses have assumed a relatively simple, scissor-like (orthal) jaw mechanism for these animals. New analyses of dental microwear, presented here, show curvilinear striations on the teeth of Leptoceratops. These features indicate a rostral to caudal orbital motion of the mandible during chewing. A rostrocaudal mandibular orbit is seen in multituberculates, haramiyid allotherians, and some rodents, and its identification in Leptoceratops gracilis is the first evidence of complex, mammal-like chewing in a ceratopsian dinosaur. The term circumpalinal is here proposed to distinguish this new style of chewing from other models of ceratopsian mastication that also involve a palinal component. This previously unrecognized complexity in dinosaurian jaw mechanics indicates that some neoceratopsian dinosaurs achieved a mammalian level of masticatory efficiency through novel adaptive solutions. PeerJ Inc. 2016-07-06 /pmc/articles/PMC4941762/ /pubmed/27441111 http://dx.doi.org/10.7717/peerj.2132 Text en ©2016 Varriale http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , 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) and either DOI or URL of the article must be cited. |
spellingShingle | Evolutionary Studies Varriale, Frank J. Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title | Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title_full | Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title_fullStr | Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title_full_unstemmed | Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title_short | Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis |
title_sort | dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur leptoceratops gracilis |
topic | Evolutionary Studies |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941762/ https://www.ncbi.nlm.nih.gov/pubmed/27441111 http://dx.doi.org/10.7717/peerj.2132 |
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