皖北地区寒武系芙蓉统三叶虫褶盾虫属Ptychaspis及其种内差异

TRILOBITE PTYCHASPISFROM THE CAMBRIAN FURONGIAN IN NORTHERN ANHUI AND ITS INTRASPECIFIC VARIATIONS

在安徽省萧县凤凰山剖面采得若干褶盾虫属Ptychaspis标本,包括Ptychaspis ceto Walcott,1905和P.calchas Walcott,1905两个种。通过对比该属模式种及其他种,认为过去中国绝大多数的已建种都应归入这两个种中,并表现为这两个种较大的种内差异(头鞍形状、鞍沟、眼叶大小、前边缘、面线、后侧翼以及活动颊表面纹饰等),同时对这两个种的种内差异进行简要讨论。

The strata of Fengshanian （Cambrian, Furongian） are well deposited in northern Anhui, China. Ptychaspis ceto Walcott, 1905 and P. calchas Walcott, 1905 are described herein based on the recently collected specimens including disarticulated cranidia, librigena and pygidia from the Fenghuangshan in Xiaoxian of Anhui. A brief discussion of the intraspecific variations （e. g. , shape of glabella, glabella furrows, eye lobes, anterior margin, facial sutures, posterior-lateral limbs and shell ornamentation, etc. ） in these two species are also provided, indicated that most species of Ptychaspis described before are based on the intraspecific variations instead of the interspecific varia tions.