Trilobita - Proetida - Hystricuridae
Parent taxon: Proetida according to J. C. Lamsdell and P. A. Selden 2015
See also Adrain 2011, Fortey and Bruton 2013 and Jell and Adrain 2002
Sister taxa: Aulacopleuroidea, Bathyuridae, Bathyuroidea, Cammingella, Dimeropygidae, Huanoproetus, Niachangella, Parapalebralia, Phaselops, Proetoidea, Pusillaboles, Radonia, Sperginaspis, Tayanaella, Tekinia, Telephinidae, Vitaella
Subtaxa: Amblycranium Etheridgaspis Glabretina Guizhouhystricurus Hillyardininae Hintzecurinae Holubaspis Hystricurinae Hystricurus Litzicurus Millardicurus Nyaya Omuliovia Paenebeltella Parahystricurus Paraplethopeltis Psalikilus Rollia Svalbardicurus Taoyuania Tasmanaspis
Ecology: fast-moving low-level epifaunal deposit feeder
Distribution:
• Ordovician of Australia (15 collections), Canada (59: Alberta, Newfoundland, Newfoundland and Labrador), China (11), the Czech Republic (4), France (5), Greenland (5), Norway (1), the Russian Federation (14), South Korea (4), United States (173: Alaska, California, Idaho, Missouri, Montana, Nevada, New Mexico, New York, North Dakota, Texas, Utah, Vermont, Virginia)
• Cassinian of Canada (2: Quebec)
• Arenig of Argentina (1), Canada (1: Newfoundland and Labrador), China (1), Greenland (3), the Russian Federation (1), United States (4: Montana, Nevada, North Dakota)
• Jefferson of United States (1: Missouri)
• Canadian of Canada (2: Newfoundland), China (5), United States (2: Maryland)
• Jeffersonian of Canada (2: Newfoundland, Newfoundland and Labrador), United States (2: Oklahoma)
• Cambrian to Ordovician of the Russian Federation (1)
• Cambrian of China (3), United States (3: Texas, Utah)
Total: 325 collections including 529 occurrences