Rhynchonellata - Orthida - Orthidiellidae
Parent taxon: Orthoidea according to J. Hansen and L. E. Holmer 2011
See also Rubel 1961, Williams et al. 2000 and Wright 1964
Sister taxa: Anomalorthidae, Archaeorthidae, Bajanorthis, Bohemiellidae, Cathaysiorthidae, Glyptorthidae, Hesperonomiidae, Hesperorthidae, Lycophoriidae, Malinella, Nugnecella, Orthidae, Ottadalenites, Plaesiomyidae, Poramborthidae, Productorthidae, Skenidioidae, Tarfayidae, Turarella, Whittardiidae, Zhejiangorthis, Dolerorthidae, Toxorthidae, Dinorthidae
Subtaxa: Eostrophomena Orthidiella Orthidium Portranella Trematorthis Tuvinia
Ecology: stationary epifaunal suspension feeder
Distribution:
• Whiterockian of United States (15: Nevada collections)
• Chazyan of United States (14: New York, Vermont)
• Billingen of Estonia (1), the Russian Federation (2)
• Arenig of Argentina (3), China (2)
• Arenigian of Canada (1: Northwest Territories)
• Ordovician of Argentina (5), Belgium (11), China (2), Estonia (1), France (2), Ireland (2), Kazakhstan (9), Norway (6), Portugal (3), the Russian Federation (5), Spain (3), Sweden (2), the United Kingdom (5), United States (30: California, Nevada, Tennessee, Utah)
Total: 124 collections including 145 occurrences