†order Athyridida Boucot et al. 1964 (lamp shell)
Parent taxon: Rhynchonellata according to A. 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