Parent taxon: Heliolitida according to D. Hill 1981
Sister taxa: Coccoseridicae, Heliolitina
Subtaxa: Halysitidae
Ecology: stationary epifaunal suspension feeder-photosymbiotic
Distribution:
• Devonian of Canada (1: New Brunswick collection), United States (3: Indiana, Kentucky)
• Jaani of Estonia (5)
• Niagaran of United States (2: Indiana, Ohio)
• Silurian of Afghanistan (1), Australia (3), Belarus (2), Canada (88: British Columbia, Manitoba, New Brunswick, Northwest Territories, Northwest Territories and Yukon, Nunavut, Ontario, Quebec, Québec), China (26), the Czech Republic (8), Estonia (33), India (5), Ireland (1), Kazakhstan (1), Mongolia (11), Norway (8), the Russian Federation (46), Svalbard and Jan Mayen (1), Sweden (49), Turkey (1), Ukraine (6), the United Kingdom (6), United States (93: Alaska, California, Illinois, Indiana, Iowa, Kentucky, Michigan, Nebraska, Nevada, New York, Ohio, Oklahoma, Pennsylvania, Wisconsin), Uzbekistan (1), Venezuela (1)
• Ordovician to Silurian of Canada (4: British Columbia, Northwest Territories, Québec), United States (1: Alaska)
• Ordovician of Australia (7), Belarus (1), Canada (83: Manitoba, Northwest Territories, Nunavut, Quebec, Québec), China (25), Estonia (43), Kazakhstan (2), Latvia (5), Lithuania (3), Malaysia (1), Mongolia (5), Norway (2), the Russian Federation (31), the United Kingdom (2), United States (26: Alaska, California, Colorado, Michigan, Missouri, Nevada, New Mexico, Texas, Wyoming)
• Ibexian of United States (1: Nevada)
Total: 644 collections including 884 occurrences