†family Sphenotretidae Savage 1996 (lamp shell)
Rhynchonellata - Rhynchonellida - Sphenotretidae
Parent taxon: Ancistrorhynchoidea according to A. Williams et al. 2002
Sister taxa: Ancistrorhynchidae, Niorhynicidae, Oligorhynchiidae
Subtaxa: Altaethyrella Dorytreta Sphenotreta
Type: Sphenotreta
Ecology: stationary epifaunal suspension feeder
Distribution:
• Whiterockian of United States (1: Nevada collection)
• Chazyan of Canada (5: Ontario, Quebec), United States (27: New York, Tennessee, Vermont)
• Ordovician of Canada (1: Quebec), China (25), Kazakhstan (8), Norway (1), the Russian Federation (2), the United Kingdom (1), United States (11: Nevada, Virginia)
Total: 82 collections including 83 occurrences