†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:
• Ordovician of Canada (4: Quebec collections), China (25), Kazakhstan (8), Norway (1), the Russian Federation (2), the United Kingdom (1), United States (13: Nevada, Tennessee, Virginia)
• Chazy of Canada (2: Ontario, Quebec), United States (25: New York, Vermont)
• Whiterockian of United States (1: Nevada)
Total: 82 collections including 83 occurrences