Parent taxon: Opisthobranchia according to J. J., Jr. Sepkoski 2002
Sister taxa: Acanthotrophia, Acochlidea, Buscotypus, Canepina, Cephalaspida, Cephalaspidea, Cylindrobullinoidea, Floribella, Gymnosomata, Heteroptygmatis, Lutima, Mariottia, Mistostigma, Nicosiaella, Notaspidea, Paronaella, Pseudofusia, Reticulacella, Rhodopemorpha, Scorbinidola, Tectibranchia, Thecosomata, Umbraculomorpha
Subtaxa: Acrostylus Ampezzamilda Ampezzogyra Aphanotaenia Auristomia Babella Bactroptyxis Boehmiola Brouzetia Campanelle Campichia Camponeila Cassianaxis Cassianilda Coemansia Colpostomia Costaella Costosyrnola Crimella Cryptoplocus Curetia Cyclodostomia Diptyxiella Discobasis Doliella Dolomitella Egilina Elatioriella Eleganella Endiaplocus Euparthenia Eustomia Falsostyliola Faluniella Fibulella Fibuloptygmatis Fibuloptyxis Fusiptyxis Gemmellaroia Goniodostomia Gonzagia Haploptyxis Heida Iphiana Italoptygmatis Itruvia Jaccardiella Lacriforma Laevinerinea Laeviselica Loxoptyxis Macrodostomia Melanioptyxis Mrhilaia Neonerinea Neoptyxis Nerineoptyxis Nipteraxis Nisiturris Nisostomia Obexomia Odetta Odostomidea Oligoptyxis Pachysyrnola Paleoalvania Parasimplotyxis Partulida Pentaptyxis Phasianema Planpyrgiscus Ptygmatis Pyramistomia Pyrgiscilla Raulinia Ravnostomia Rissopsetia Rugiferia Sequania Sinustomia Sollariaxis Spirocyclina Sulcorinella Taphrostomia Tauricella Teleoptyxis Terelimella Tiberia Trimalaxis Trochalia Tropaeas Ulfa Upella Valanginella Voluspa
Ecology: epifaunal
Distribution:
• Quaternary of Japan (1 collection), Mayotte (2)
• Pliocene of Belgium (2), Panama (1)
• Miocene of France (1), New Zealand (1)
• Oligocene of Denmark (1), France (1), Germany (1)
• Eocene of France (5), New Zealand (1), the United Kingdom (4), United States (5: Texas)
• Paleocene of Australia (1), Belgium (1), Denmark (3), Greenland (3), United States (1: Texas)
• Cretaceous of Albania (2), Angola (2), Egypt (7), France (3), Greece (1), Hungary (3), Italy (1), Portugal (2), Spain (2), Switzerland (1), USSR (1), Ukraine (2)
• Jurassic of Austria (1), China (2), Cuba (1), Ethiopia (1), France (3), Germany (2), Iran (1), Israel (1), Kenya (3), Poland (3), Portugal (5), Saudi Arabia (6), Switzerland (1), the United Kingdom (2)
• Triassic of Hungary (3), Italy (9), United States (1: Alaska)
• Permian of Malaysia (1)
Total: 108 collections including 131 occurrences