Alternative spelling: Cyrtodontacea
Parent taxon: Cyrtodontidina according to J. G. Carter et al. 2011
See also Bailey 1983, Bouchet et al. 2010, Newell 1965, Ride et al. 1999 and Vokes 1980
Sister taxa: Falcatodontoidea, Pichlerioidea
Subtaxa: Cyrtodontidae
Ecology: facultatively mobile epifaunal suspension feeder
Distribution:
• Permian of Australia (3 collections), Oman (8)
• Virgilian of United States (1: Maryland)
• Carboniferous of China (1), France (1), the Russian Federation (1), United States (1: Maryland)
• Devonian of Brazil (1), Canada (1: Quebec), Ghana (1), New Zealand (2), the United Kingdom (1), United States (4: New York, Pennsylvannia)
• Silurian of Canada (1: Ontario), China (5), the Czech Republic (1), Jordan (1), Sweden (2), the United Kingdom (4), United States (16: Iowa, New York, Wisconsin)
• Ordovician of Argentina (1), Australia (20), Canada (47: British Columbia, Nunavut, Ontario, Quebec), China (10), the Czech Republic (1), Morocco (1), Norway (21), Spain (1), Sweden (6), the United Kingdom (11), United States (117: Colorado, Illinois, Illinois, Iowa, Indiana, Kentucky, Michigan, Minnesota, Minnesota, Illinois, Iowa, Minnesota, Iowa, Wisconsin, Illinois, Minnesota, Wisconsin, Illinois, Missouri, New York, Ohio, Tennessee, Virginia, Wisconsin, Wisconsin, Illinois, Iowa)
• Chazy of Canada (3: Ontario, Quebec), United States (6: New York)
• Whiterockian of United States (1: Minnesota)
Total: 302 collections including 480 occurrences