Parent taxon: Agnostina according to R. Lerosey-Aubril et al. 2020
See also Bruton and Harper 2000, Palmer and Halley 1979, Pour and Popov 2009 and Westrop et al. 1996
Sister taxa: Agnostogonus, Armagnostus, Blystagnostus, Condylopygoidea, Delagnostus, Dignagnostus, Grandagnostus, Hastagnostus, Phoidagnostus, Quadragnostidae, Skryjagnostus
Subtaxa: Hypagnostoidae Peronopsidae
Ecology: nektonic suspension feeder
Distribution:
• Dobrotivian of Czechia (1 collection)
• Ordovician of Argentina (9), Canada (2: Quebec), China (7), Czechia (1), Denmark (1), Poland (1), Sweden (3), the United Kingdom (3), United States (1: Maine)
• Cambrian of Antarctica (1), Argentina (1), Australia (9), Canada (42: Alberta-British Columbia, Brithish Columbia, British Columbia, Newfoundland and Labrador, Northwest Territories, Quebec), China (18), Czechia (9), Denmark (3), France (1), Greenland (12), India (2), Iran (1), Italy (1), Kazakhstan (24), Mexico (1), Morocco (1), Norway (2), Poland (1), the Russian Federation (4), Spain (5), Sweden (5), Türkiye (4), the United Kingdom (5), United States (76: Alaska, California-Nevada, Georgia, Idaho, Montana, Nevada, Nevada and California, New York, Pennsylvania, South Carolina, Utah, Vermont)
• Templetonian of Australia (4), United States (1: Nevada)
• Amgan of Kazakhstan (5), Kyrgyzstan (1), Norway (1), the Russian Federation (8), United States (2: Utah)
• Solvan of Australia (2), Canada (24: Newfoundland and Labrador), Czechia (4), Spain (1)
Total: 310 collections including 407 occurrences