Artiopoda - Asaphida - Symphysurinidae
Parent taxon: Cyclopygoidea according to R. A. Fortey and D. L. Bruton 2013
Sister taxa: Cyclopygidae, Nileidae, Taihungshaniidae
Subtaxa: Eurysymphysurina Randaynia Symphysurina
Type: Symphysurina
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Ordovician of Canada (48: Alberta, British Columbia, Newfoundland, Newfoundland and Labrador, Yukon collections), France (2), Greenland (4), Norway (2), Sweden (3), United States (32: California, Idaho, Montana, Nevada, New Mexico, New York, Oklahoma, Texas, Utah, Vermont)
• Skullrockian of Canada (22: British Columbia, Newfoundland), Greenland (1), United States (25: New York, Texas, Utah)
• Cambrian of Canada (4: Newfoundland and Labrador), United States (10: Texas, Utah)
Total: 153 collections including 178 occurrences