†order Athyridida Boucot et al. 1964 (lamp shell)
Parent taxon: Rhynchonellata according to L. Hints and D. A. T. Harper 2015
See also Williams et al. 2000
Sister taxa: Atrypida, Cadomelloidea, Cardiarinidae, Dentatrypa, Mongolellidae, Orthida, Pentamerida, Protorthida, Rhynchonellida, Spiriferida, Spiriferinida, Terebratulida, Thecideida, Tropidoleptidae
Subtaxa: Anoplothecoidea Athyrididina Dayioidea Koninckinidina Retziidina Uncitoidea
Ecology: stationary low-level epifaunal suspension feeder