A NEW LATE JURASSIC DOCODONT （MAMMALIA） FROM NORTHEASTERN XINJIANG, CHINA

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	A NEW LATE JURASSIC DOCODONT （MAMMALIA） FROM NORTHEASTERN XINJIANG, CHINA
	HU YaoMing 1; MENG Jin1 ; James M CLARK 2
	2007
发表期刊	VERTEBRATA PALASIATICA
ISSN	1000-3118
卷号	45 期号:3 页码:173
摘要	A new genus and species of docodontid(Docodonta,Mammalia),Acuodulodon sunae, represented by a partial left lower jaw and dentition,is described.It is from the upper part of the Shi- shugou Formation in the Wucaiwan area of the Junggar Basin in northeastern Xinjiang,China,with an estimated age of 159～161 Ma(Oxfordian,early Late Jurassic).The new mammal is typical of docodonts in having a cusp b in front of cusp a,a cusp c distolingual to cusp a and a cusp g mesiolin- gual to cusp a on lower molariforms.Differing from other docodonts,it has no cusp e or crest b-e de- veloped on lower molariforms.Unique among docodonts,cusps a and c of the new animal maintained their sharpness while cusp g and crest b-g wore away fast,indicating that both shearing and crush- ing/grinding occurred in the chewing cycle and probably last for most of the life span of the animal. Phylogenetic analysis of a data matrix with 24 lower molariform characters across 15 taxa recovers a monophyletic Docodonta,which has distinct diagnostic:characters in lower molariforms.Within doco- donts,Docodon and Borealestes are successively basal to other docodonts;Acuodulodon and Itatodon +(Simpsonodon,Castorocauda+(Tegotherium+Sibirotherium))form a monophyletic clade. Tegotheriid genera are nested within Docodontidae,but a monophyletic tegotheriid clade composed of Tegotherium,Sibirotherium,Itatodon,and Tashkumyrodon is not recovered.The dentary of Acuodu- Iodon is typical of docodonts.It has a shallow postdentary trough and a wide and sharp medial ridge, both of which do not extend onto the medial side of the condylar peduncle,indicating looser contact between postdentary bones and the dentary than in morganucodontids,a more derived condition in the evolution toward the definitive mammalian middle ear.
关键词	新疆晚侏罗世柱齿兽目尖钝齿兽系统发育 Xinjiang Late Jurassic Docodonta Acuodulodon phylogeny
语种	英语
文献类型	期刊论文
条目标识符	http://119.78.100.205/handle/311034/22350
专题	中国科学院古脊椎动物与古人类研究所
作者单位	1.中国科学院古脊椎动物与古人类研究所 2.Division of Paleontology, American Museum of Natural History New York NY
第一作者单位	中国科学院古脊椎动物与古人类研究所
推荐引用方式 GB/T 7714	HU YaoMing,MENG Jin,James M CLARK. A NEW LATE JURASSIC DOCODONT （MAMMALIA） FROM NORTHEASTERN XINJIANG, CHINA[J]. VERTEBRATA PALASIATICA,2007,45(3):173.
APA	HU YaoMing,MENG Jin,&James M CLARK.(2007).A NEW LATE JURASSIC DOCODONT （MAMMALIA） FROM NORTHEASTERN XINJIANG, CHINA.VERTEBRATA PALASIATICA,45(3),173.
MLA	HU YaoMing,et al."A NEW LATE JURASSIC DOCODONT （MAMMALIA） FROM NORTHEASTERN XINJIANG, CHINA".VERTEBRATA PALASIATICA 45.3(2007):173.