Time: Early Cambrian (~525 million years ago)
Site: Chengjiang Maotianshan Shales, Qiongzhusi Section, Yu'anshan
Member, Heilinpu Formation, Maotianshan Hill, Yuxi, Chengjiang County,
Yunnan Province, China
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.
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