Clypecaris pteroidea, a Rare Shelled Arthropod from Chengjiang

The systematic position of this taxon has undergone several revisions. It was established as the sole member of the Family Clypercarididae, and was originally known from only one specimen. Those from Chengjiang have been called Ercaicunia multinodosa, but some scientists believe that to be a junior synonym of Clypecaris. It differs from the more common genus Waptia in having a higher number of body segments. While the species is known from other Lower Cambrian locations such as Haikou, those from the Chengjiang Biota are rare, and are known to show the best soft part preservation (notice the gut line and segmentation), making it a special specimen of a rare taxon.

Reference: Hou X., New rare bivalved arthropods from the Lower Cambrian Chengjiang fauna, Yunnan, China, Journal of Paleontology; January 1999; v. 73; no. 1; p. 102-116