Lingulata - Acrotretida - Ceratretidae
Parent taxon: Acrotretoidea according to A. Williams et al. 2000
See also Holmer and Popov 1990 and Puura and Holmer 1993
Sister taxa: Acrothyra, Acrotretidae, Craniotreta, Curticiidae, Eoconulidae, Ephippelasmatidae, Hadrotreta, Scaphelasmatidae, Schizotretoides, Torynelasmatidae, Acrotetidae
Subtaxa: Almohadella Bozshakolia Ceratreta Ephippelasmatinae Keyserlingia Kleithriatreta
Ecology: stationary epifaunal suspension feeder
Distribution:
• Ordovician of Estonia (1 collection), Ireland (1), Sweden (1)
• Cambrian to Ordovician of Estonia (11)
• Cambrian of Canada (2: British Columbia), Estonia (17), Finland (1), Kyrgyzstan (1), the Russian Federation (2), Sweden (5), United States (1: Montana)
• Amgan of the Russian Federation (1)
• Solvan of Australia (1), the Czech Republic (1), Kazakhstan (1)
Total: 47 collections each including a single occurrence