Juvenile Branchiocaris Shelled Arthropod Fossil from Utah

This unusual Phyllocarid arthropod is known as Branchiocaris pretiosa. Phyllocarids are one of the lesser known branchiopod crustaceans from the Cambrian where they are among the earliest animals with a hard shell. They have a fairly large carapace, which protects the anterior part of the body. This structure hinged along the dorsal edge like a bivalve. Usually only the carapace is found. Branchiocaris has been placed by some as a near relative of Marella of the Burgess Shale, an assignment not agreed to by all researchers. The taxon is also known from the Burgess Shale of British Columbia, while another member of the genus has been found in the Chengjiang Biota.