Rhynchonellata - Orthida - Plaesiomyidae
Parent taxon: Plaesiomyidae according to M. Liljeroth et al. 2017
See also Mitchell 1977, Williams et al. 2000 and Zuykov et al. 2008
Sister taxa: Bokotorthis, Evenkininae, Metorthinae
Subtaxa: Austinella Campylorthis Chaulistomella Dinorthis Madiorthis Multicostella Plaesiomys Retrorsirostra Valcourea
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 (12: Nevada)
• Arenig of Bolivia (3), Canada (1: New Brunswick), China (2)
• Ordovician to Silurian of United States (1: California)
• Ordovician of Argentina (5), Australia (19), Belarus (2), Bolivia (5), Canada (126: British Columbia, Manitoba, Northwest Territories, Nunavut, Nunvait, Ontario, Quebec), China (13), Estonia (20), France (1), Ireland (5), Kazakhstan (23), Myanmar (1), Norway (4), Peru (1), Poland (1), the Russian Federation (21), 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)
• Ibexian of United States (1: Nevada)
Total: 754 collections including 956 occurrences