Parent taxon: Modiomorphoida according to H. E. Vokes 1980
Sister taxa: Brahcylyrodesma, Caspiconcha, Junjagiana, Modiomorphoidea, Rimmyjmima
Subtaxa: Allodesmatidae Carydiidae Lamellodontidae
Type: Cycloconchidae
Ecology: stationary semi-infaunal suspension feeder
Distribution:
• Carboniferous of United States (1: California collection)
• Devonian of Canada (1: New Brunswick), Germany (3), Luxembourg (2), Poland (1), the United Kingdom (2), United States (47: New York, Pennsylvania)
• Silurian of Bolivia (1), Brazil (1), Canada (1: Ontario), China (2), Paraguay (1), the United Kingdom (4)
• Ordovician of Canada (4: Ontario), China (1), Norway (1), Sweden (1), United States (30: Indiana, Maryland, Minnesota, Minnesota, Illinois, Iowa, Missouri, New York, Ohio, Virginia)
Total: 104 collections including 106 occurrences