Helcionelloida - Helcionellida
Full reference: B. Runnegar and P.A. Jell. 1976. Australian Middle Cambrian molluscs and their bearing on early molluscan evolution. Alcheringa 1(1/2):109-138
Parent taxon: Helcionellida according to P. J. Wagner 2023
See also Bouchet et al. 2005, Parkhaev 2002 and Parkhaev and Demidenko 2010
Sister taxa: Coreospiridae, Helcionelloidea, Pelagiellidae, Tribelopoma
Subtaxa: Rugaeconidae Trenellidae Yochelcionellidae
Type: Yochelcionellidae
Ecology: slow-moving low-level epifaunal grazer
Distribution:
• Cambrian to Ordovician of Poland (1 collection)
• Cambrian of Antarctica (5), Australia (29), Canada (6: Newfoundland and Labrador, Northwest Territories, Quebec), China (20), Denmark (1), France (2), Germany (2), Greenland (21), Kazakhstan (1), Kyrgyzstan (2), Mexico (2), New Zealand (1), Poland (1), the Russian Federation (27), Spain (1), the United Kingdom (1), United States (8: Idaho, Massachusetts, New York, Pennsylvania, Utah)
• Solvan of Morocco (3), the Russian Federation (4)
• Amgan of the Russian Federation (2)
Total: 140 collections including 190 occurrences