Parent taxon: Ptychopariina according to F. A. Sundberg and L.B. McCollum 2003
See also Landing et al. 2008, Pour and Popov 2009 and Sundberg and McCollum 2000
Sister taxa: Conocoryphacea, Guizhoucephalina, Huaiaspis, Leiostegiacea, Liostracinoidea, Luaspididae, Paraantagmus, Ptychoparioidea, Yuknessaspis
Subtaxa: Elrathina Eokochaspis Hadrocephalites Kochina Mexicella
Ecology: fast-moving low-level epifaunal deposit feeder
Distribution:
• Cambrian of Argentina (1 collection), Canada (38: Alberta, Alberta-British Columbia, Brithish Columbia, British Columbia, Newfoundland, Northwest Territories, Northwest Territory), Mexico (3), United States (102: Arizona, California, California-Nevada, Georgia, Idaho, Montana, Nevada, Nevada and California, Pennsylvania, Utah, Vermont)
• Amgan of United States (2: Utah)
• Solvan of Canada (11: British Columbia, Newfoundland and Labrador), United States (75: Nevada)
Total: 232 collections including 260 occurrences