PeerJ. 2016 Jul 06;4:e2132. doi: 10.7717/peerj.2132. eCollection 2016.
Dental microwear reveals mammal-like chewing in the neoceratopsian dinosaur Leptoceratops gracilis.
PeerJ
Frank J Varriale
Affiliations
Affiliations
- Department of Biology, King's College , Wilkes-Barre , PA , United States.
PMID: 27441111
PMCID: PMC4941762 DOI: 10.7717/peerj.2132
Abstract
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.
Keywords: Ceratopsia; Chewing; Dental microwear; Dinosauria; Jaw action; Jaw mechanics; Mastication; Ornithischia
References
- Am J Phys Anthropol. 1999 Mar;108(3):359-73 - PubMed
- Nature. 2001 Jun 7;411(6838):684-7 - PubMed
- Biol Rev Camb Philos Soc. 2001 Aug;76(3):411-47 - PubMed
- Naturwissenschaften. 2007 Jan;94(1):71-5 - PubMed
- Proc Biol Sci. 2008 Nov 7;275(1650):2483-90 - PubMed
- J Morphol. 2009 Aug;270(8):903-20 - PubMed
- Proc Biol Sci. 2010 Jan 22;277(1679):199-209 - PubMed
- Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11194-9 - PubMed
- Anat Rec (Hoboken). 2009 Sep;292(9):1246-65 - PubMed
- Anat Rec (Hoboken). 2009 Sep;292(9):1352-69 - PubMed
- Nature. 2010 Aug 5;466(7307):748-51 - PubMed
- PLoS One. 2011 Apr 06;6(4):e18304 - PubMed
- Anat Rec (Hoboken). 2012 Jun;295(6):968-79 - PubMed
- Science. 2012 Oct 5;338(6103):98-101 - PubMed
- Zookeys. 2012;(226):1-225 - PubMed
- Anat Rec (Hoboken). 2014 Jul;297(7):1165-80 - PubMed
- PLoS One. 2014 Jun 11;9(2):e98605 - PubMed
- Arch Oral Biol. 1989;34(12):929-36 - PubMed
- Sci Adv. 2015 Jun 05;1(5):e1500055 - PubMed
- Evolution. 1966 Sep;20(3):290-308 - PubMed
- Scanning Microsc. 1988 Jun;2(2):1149-66 - PubMed
- Scanning Microsc. 1988 Jun;2(2):1167-75 - PubMed
- Adv Anat Embryol Cell Biol. 1984;87:1-109 - PubMed
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