Trilobita - Ptychopariida - Alokistocaridae

Full reference: C. E. Resser. 1938. Middle Cambrian fossils from Pend Oreille Lake, Idaho. Smithsonian Miscellaneous Collections 97(3):1-12

Belongs to Elrathia according to C. E. Resser 1938

Sister taxa: Elrathia hoboi, Elrathia idahoensis, Elrathia longiceps, Elrathia rara, Elrathia spencei

Type specimen: USNM 95035. Its type locality is Locality 37m, shale beds (Pend Oreille Lake), which is in a Cambrian carbonate shale/limestone in the Rennie Shale Formation of Idaho.

Ecology: fast-moving epifaunal detritivore