Rhynchonellata - Orthida - Plaesiomyidae
Parent taxon: Orthoidea according to M. Liljeroth et al. 2017
See also Howe 1988, Macomber 1970, Mitchell 1977, Popov et al. 2000, Potter 1990, Williams et al. 2000 and Zuykov et al. 2008
Sister taxa: Anomalorthidae, Archaeorthidae, Bajanorthis, Bohemiellidae, Cathaysiorthidae, Glyptorthidae, Hesperonomiidae, Hesperorthidae, Lycophoriidae, Malinella, Nugnecella, Orthidae, Orthidiellidae, Ottadalenites, Poramborthidae, Productorthidae, Skenidioidae, Tarfayidae, Turarella, Whittardiidae, Zhejiangorthis, Dolerorthidae, Dinorthidae
Subtaxa: Bokotorthis Evenkininae Metorthinae Plaesiomyinae
Ecology: stationary epifaunal suspension feeder
Distribution:
• Silurian of Sweden (6 collections)
• Uhaku of the Russian Federation (1)
• Chazyan of Canada (19: Northwest Territories, Ontario, Quebec), United States (57: New York, Tennessee, Virginia)
• Whiterockian of United States (13: California, Nevada)
• Dawan of China (2)
• Arenig of Bolivia (3), Canada (1: New Brunswick), China (5)
• Ordovician to Silurian of United States (1: California)
• Ordovician of Argentina (5), Australia (19), Belarus (2), Bolivia (5), Canada (127: British Columbia, Manitoba, Northwest Territories, Nunavut, Nunvait, Ontario, Quebec), China (17), Estonia (20), France (1), Ireland (5), Kazakhstan (29), Myanmar (1), Norway (4), Peru (1), Poland (1), the Russian Federation (26), the United Kingdom (53), United States (351: Alaska, California, Colorado, Georgia, Idaho, Illinois, Illinois, Iowa, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, Nevada, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Virginia, Wisconsin, Wyoming)
• Tremadoc of China (2)
• Ibexian of United States (1: Nevada)
Total: 778 collections including 989 occurrences