cambriantrilobiteovatoryctocaragranulatatchernysheva1962anditsbiostratigraphicsignificance

NIGPAS OpenIR

	cambriantrilobiteovatoryctocaragranulatatchernysheva1962anditsbiostratigraphicsignificance
	Jinliang Yuan 1; Yuanlong Zhao 2; Jin Peng 2; Xuejian Zhu 1; Jihpai Lin 3
	2009-01-01
发表期刊	progressinnaturalscience
ISSN	1002-0071
卷号	19 期号:2 页码:213
摘要	The genus Ovatoryctocara Tchernysheva, 1962, and its key species Ovatoryctocara granulata Tchernysheva, 1962, are revised. Ovatoryctocara granulata occurs near the base of the Ovatoryctocara Zone and ranges up into the lower portion of the Kounamkites Zone in the Siberian Platform. O. granulata also appears in southeastern Guizhou, South China, but O. granulata in northern Greenland may represent an indefinite species. Specimens of Ovatoryctocara from Newfoundland cannot be identified to species level. Specimens including two cranidia and three pygidia from the lower part of the Aoxi Formation at Yaxi Village, Shizhu Town, eastern Tongren, northeastern Guizhou, were previously assigned to O. granulata , which is now reassigned as a new species O. yaxiensis sp. nov. It bears the following main features: glabella club-shaped, slightly expanded medially, with four pairs of lateral furrows, of which S1–S3 are triangular pits, S4 is shallow, connecting with axial furrow; shorter palpebral lobe situated a little anterior to the midway of facial suture across the fixigenae, longer posterolateral area (exsag.); semielliptical pygidium consisting of seven axial rings with a terminal piece and with eight pairs of marginal tips giving a sawtooth-like shape of the lateral margins in dorsal view. Although O. granulata is a widely distributed species, the FAD of O . granulata , for a global stage boundary, still has some disadvantages. First, its distribution is not as wide as that of Oryctocephalus indicus (Reed, 1910). Second, specimens of O. granulata are common only in Siberia. Third, the stratigraphic range of the species has not been studied in detail in all continents. Fourth, O. granulata is relatively small and easily affected by post-burial distortion. Last but not least, there exists obviously a facies change between the Ovatoryctocara Zone (lower Amgan Stage; deeper water facies) and the underlying Anabaraspis splendens Zone (Toyonian Stage; shallow water facies) in Siberian Platform. Nevertheless, the stratigraphic correlation utility of O. granulata in South China and Siberia is discussed.
语种	英语
文献类型	期刊论文
条目标识符	http://ir.nigpas.ac.cn/handle/332004/30970
作者单位	1.中国科学院南京地质古生物研究所 2.College of Resource and Environment Science,Guizhou University 3.School of Earth Sciences,Ohio State University
推荐引用方式 GB/T 7714	Jinliang Yuan,Yuanlong Zhao,Jin Peng,et al. cambriantrilobiteovatoryctocaragranulatatchernysheva1962anditsbiostratigraphicsignificance[J]. progressinnaturalscience,2009,19(2):213.
APA	Jinliang Yuan,Yuanlong Zhao,Jin Peng,Xuejian Zhu,&Jihpai Lin.(2009).cambriantrilobiteovatoryctocaragranulatatchernysheva1962anditsbiostratigraphicsignificance.progressinnaturalscience,19(2),213.
MLA	Jinliang Yuan,et al."cambriantrilobiteovatoryctocaragranulatatchernysheva1962anditsbiostratigraphicsignificance".progressinnaturalscience 19.2(2009):213.