Artiopoda - Agnostida - Diplagnostidae
Parent taxon: Condylopygoidea according to E. B. Naimark and T. V. Pegel 2017
See also Bao and Jago 2000, Bruton and Harper 2000 and Whittington et al. 1997
Sister taxa: Agnostidae, Ammagnostidae, Clavagnostidae, Condylopygidae, Doryagnostidae, Glaberagnostus, Glyptagnostus, Leiagnostus, Megagnostus, Metagnostidae, Phalacromidae, Phalagnostus, Phaldagnostus, Pseudagnostidae, Ptychagnostidae, Spinagnostidae, Valenagnostus
Subtaxa: Acadagnostus Agnostotes Baltagnostus Denagnostus Diplagnostinae Diplagnostus Dolichagnostus Iniospheniscus Linguagnostus Machairagnostus Nahannagnostus Oedorhachis Oidalagnostinae Pseudagnostus Xestagnostus
Ecology: slow-moving epifaunal detritivore
Distribution:
• Arenigian of China (1 collection)
• Ordovician of Argentina (8), Bolivia (2), Canada (2: Newfoundland and Labrador), Mexico (2), the United Kingdom (1), United States (3: Texas, Vermont)
• Skullrockian of Argentina (1)
• Taoyuanian of China (42), the Russian Federation (18), South Korea (53)
• Cambrian to Ordovician of Argentina (1), the Russian Federation (1)
• Cambrian of Antarctica (1), Argentina (8), Australia (62), Canada (75: Alberta, British Columbia, New Brunswick, Newfoundland, Newfoundland and Labrador, Quebec, Yukon), China (167), Denmark (2), Greenland (9), India (8), Italy (1), Kazakhstan (126), New Zealand (1), the Russian Federation (14), South Korea (7), Spain (3), Sweden (3), the United Kingdom (1), United States (154: Alabama, Alaska, Arkansas, California, Georgia, Idaho, Indiana, Minnesota, Missouri, Montana, Nevada, Nevada and Utah, New York, Oklahoma, South Dakota, Tennessee, Texas, Utah, Virginia, Wisconsin, Wyoming)
• Amgan of Czechia (2), Kazakhstan (3)
• Solvan of Spain (1)
Total: 783 collections including 1180 occurrences