Tuzoia sinensis, Decorated Phyllocarid Fossil from Chengjiang

This unusual fossil is the rarely-seen Phyllocarid known as Tuzoia sinensis Yunnan Province, China. It is a bivalved crustacean, most well known for its distinctive reticulated carapace. This specimen comes from the strata immediately above the Chengjiang Boita, and is therefore slightly younger, and more near the age of the Burgess Shale Fauna of British Columbia. The genus is known from the Burgess Shale and from Early/Middle Cambrian deposits of Utah. Those are largely distinguished by the presence and placement of spines on the carapace. Few examples of the genus are known from more than the carapace, as seen here. Notice that there are a few circles present on the shell that are far different than the reticulation. These are traces of brachiopods, most likely Diandongia making for a fine association piece. Their shells were not resistant enough to be preserved, so all we see are their outlines.

Also see: Chengjiang Biota Cambrian Explosion