HELCIONELLOID MOLLUSK FROM THE LOWER CAMBRIAN HEILINPU FORMATION, CHENGJIANG, YUNNAN

A small cap shaped fossil from the Shiyantou and Yuanshan Members of the Heilinpu Formation (Lower Cambrian) of eastern Yunnan, China, is here referred to the new species Helcionella yunnanensis. The holotype of the species represents the first record of a helcionelloid mollusk from strata yielding the Chengjiang Biota in the upper part of the Heilinpu Member. Its stratigraphic range, based on two occurrences, is through the upper part of the Meishucunian Stage and into the Qiongzhusian Stage. Rarity of the species in the Yuanshan Member of the Heilinpu Formation may be related to fluctuating environmental condition associated with the inferred tidally influenced, coastal marine depositional environment in which the Chengjiang Biota was preserved.

Project Supported:

Clc Number:

Q915.817