Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda

doi:10.7717/peerj.4129

	Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda
	Button, Khai 1,2; You, Hailu3,4 ; Kirkland, James I.5; Zanno, Lindsay 1,2
刊名	PEERJ
	2017-12-11
卷号	5
关键词	Dinosaur Teeth Therizinosauria Von Ebner Dentin Enamel Microstructure Histology Tooth Growth
ISSN号	2167-8359
DOI	10.7717/peerj.4129
文献子类	Article
英文摘要	Previous investigations document functional and phylogenetic signals in the histology of dinosaur teeth. In particular, incremental lines in dentin have been used to determine tooth growth and replacement rates in several dinosaurian clades. However, to date, few studies have investigated the dental microstructure of theropods in the omnivory/herbivory spectrum. Here we examine dental histology of Therizinosauria, a clade of large-bodied theropods bearing significant morphological evidence for herbivory, by examining the teeth of the early-diverging therizinosaurian Falcarius utahensis, and an isolated tooth referred to Suzhousaurus megatherioides, a highly specialized large-bodied representative. Despite attaining some of the largest body masses among maniraptoran theropod dinosaurs, therizinosaurian teeth are diminutive, measuring no more than 0.90 cm in crown height (CH) and 0.38 cm in crown base length (CBL). Comparisons with other theropods and non-theropodan herbivorous dinosaurs reveals that when controlling for estimated body mass, crown volume in therizinosaurians plots most closely with dinosaurs of similar dietary strategy as opposed to phylogenetic heritage. Analysis of incremental growth lines in dentin, observed in thin sections of therizinosaurian teeth, demonstrates that tooth growth rates fall within the range of other archosaurs, conforming to hypothesized physiological limitations on the production of dental tissues. Despite dietary differences between therizinosaurians and hypercarnivorous theropods, the types of enamel crystallites present and their spatial distribution-i.e., the schmelzmuster of both taxa-is limited to parallel enamel crystallites, the simplest form of enamel and the plesiomorphic condition for Theropoda. This finding supports previous hypotheses that dental microstructure is strongly influenced by phylogeny, yet equally supports suggestions of reduced reliance on oral processing in omnivorous/herbivorous theropods rather than the microstructural specializations to diet exhibited by non-theropodan herbivorous dinosaurs. Finally, although our sample is limited, we document a significant reduction in the rate of enamel apposition contrasted with increased relative enamel thickness between early and later diverging therizinosaurians that coincides with anatomical evidence for increased specializations to herbivory in the clade.
WOS关键词	ENAMEL MICROSTRUCTURE ; LINE COUNTS ; DINOSAUR EVOLUTION ; TEETH ; ANATOMY ; REEVALUATION ; MANIRAPTORA ; HERBIVORY ; PATTERNS ; MARKINGS
WOS研究方向	Science & Technology - Other Topics
语种	英语
出版者	PEERJ INC
WOS记录号	WOS:000417859000003
资助机构	National Natural Science Foundation of China(41688103 ; 41472020)
内容类型	期刊论文
源URL	[http://119.78.100.205/handle/311034/8709]
专题	中国科学院古脊椎动物与古人类研究所
通讯作者	Button, Khai
作者单位	1.North Carolina State Univ, Dept Biol Sci, Raleigh, NC 27695 USA 2.North Carolina Museum Nat Sci, Paleontol, Raleigh, NC 27601 USA 3.Chinese Acad Sci, Inst Vertebrate Paleontol & Paleoanthropol, Key Lab Vertebrate Evolut & Human Origins, Beijing, Peoples R China 4.Univ Chinese Acad Sci, Coll Earth Sci, Beijing, Peoples R China 5.Utah Geol Survey, Salt Lake City, UT USA
推荐引用方式 GB/T 7714	Button, Khai,You, Hailu,Kirkland, James I.,et al. Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda[J]. PEERJ,2017,5.
APA	Button, Khai,You, Hailu,Kirkland, James I.,&Zanno, Lindsay.(2017).Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda.PEERJ,5.
MLA	Button, Khai,et al."Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda".PEERJ 5(2017).