Members of class branchiopoda are small crustaceans that sometimes have a shield or bivalve-like carapace. They are typically found in fresh-water or brackish environments where they filter feed, eat detritus or prey on smaller animals.
Tasch, P. 1969. Branchiopoda, in R. C. Moore ed., Treatise on Invertebrate Paleontology, Part R, Arthropoda 4, Volume 1. The University of Kansas and Geological Society of America. 128-191 pp.