Helcionelloida - Helcionellida
Alternative spelling: Helcionellacea
Parent taxon: Helcionellida according to P. J. Wagner 2023
See also Atkins and Peel 2004, Golikov and Starobogatov 1975, Knight et al. 1960, Parkhaev 2001, Parkhaev 2002, Parkhaev 2004, Parkhaev and Demidenko 2010, Runnegar 1990, Runnegar and Jell 1976 and Wahlman 1992
Sister taxa: Coreospiridae, Tribelopoma, Yochelcionelloidea
Subtaxa: Carinopeltidae Helcionellidae Igarkiellidae Procarinariidae
Ecology: slow-moving low-level epifaunal detritivore
Distribution:
• Ordovician of Kazakhstan (1 collection)
• Tremadoc of Kazakhstan (2)
• Solvan of Australia (2), Canada (1: British Columbia), the Czech Republic (1), Kazakhstan (1), Morocco (12), the Russian Federation (3)
• Amgan of Canada (1: Alberta), the Czech Republic (2), Denmark (1), Kyrgyzstan (1)
• Delamaran of Canada (2: British Columbia), Israel (1), Mexico (2), Morocco (3), United States (1: Virginia)
• Ordian of Australia (4)
• Placentian of United States (1: Massachusetts)
• Cambrian of Antarctica (9), Australia (58), Canada (15: Alberta, Labrador, New Brunswick, Newfoundland and Labrador, Nova Scotia, Quebec), China (99), Denmark (1), Germany (6), Greenland (15), Iran (1), Kazakhstan (7), Kyrgyzstan (3), Mexico (1), Mongolia (3), Morocco (3), New Zealand (2), North Korea (1), Norway (1), the Russian Federation (80), South Korea (1), Spain (12), Sweden (2), the United Kingdom (4), United States (34: Idaho, Indiana, Massachusetts, Nevada, New York, Pennsylvania, Tennessee, Vermont, Virginia)
Total: 400 collections including 892 occurrences