Belongs within: Macluritida.
The Raphistomatidae are an Ordovician to Early Carboniferous group of gastropods with basally narrow, dorsally flattened shells bearing a peripheral selenizone (Knight et al. 1960).
Characters (Knight et al. 1960): Base commonly narrow, anomphalous or narrowly phaneromphalous, upper surface more or less flattened; with deep V-shaped labral sinus in most species, culminating in shallow notch generating a selenizone at periphery.
<==Raphistomatidae [Raphistomatacea, Raphistomidae]
|--Scalites Emmons 1842KC60
| |--*S. angulatus Emmons 1842KC60
| `--S. aksuensis Yu & Xi 1995YX95
|--Buechelia Schlüter 1894KC60
| `--*B. goldfussi Schlüter 1894KC60
|--Arizonella Stoyanow 1948KC60
| `--*A. allecta Stoyanow 1948KC60
|--Scalitina Spriestersbach 1919 [incl. Ampulloscalites Wenz 1938]KC60
| `--*S. montana Spriestersbach 1919KC60
|--Raphistoma Hall 1847 (nom. cons.) [Raphistomatinae]BR05
| |--*R. striatum (Emmons 1842) [=Maclurea striata]BR17
| |--R. scalitoides Koken 1925YX95
| `--R. trochiscus (Meek 1870) [=Euomphalus (Raphistoma) trochiscus]W77
|--Pararaphistoma Vostokova 1955YN83 [incl. Climacoraphistoma Vostakova 1955KC60]
| |--*P. qualteriatum (Schlotheim 1820) [=Helicites qualteriatus]KC60
| `--P. kobayashii (Gortani 1934) [=Raphistoma kobayashii]YN83
|--Schizopea Butts 1926TTE93, KC60 [incl. Rhachopea Ulrich & Bridge 1931KC60, Roubidouxia Butts 1926KC60]
| |--*S. washburnei Butts 1926KC60
| `--S. typica (Ulrich & Bridge 1931)TTE93
|--Sisenna Koken 1896TTE93, KC60
| |--*S. turbinata (Hörnes 1855) [=Pleurotomaria turbinata]KC60
| |--S. subturrita (Deslongchamps 1849)TTE93
| `--S. turrita (Deslongchamps 1849)TTE93
|--Ceratopea Ulrich 1911 [Ceratopeidae]BR05
| |--*C. keithi Ulrich 1911KC60
| |--C. buttsi Yochelson & Bridge 1957RFD04
| |--C. canadensis (Billings 1865)RFD04
| |--C. hami Yochelson & Bridge 1957RFD04
| |--C. hammsi (Stauffer 1937)RFD04
| |--C. laurentia (Billings 1865)RFD04
| |--C. pygmaea (Stauffer 1937)RFD04
| `--C. unguis Yochelson & Bridge 1957RFD04
`--Trepospira Ulrich & Scofield 1897X97 [incl. Kansana Tasch 1953KC60]
|--*T. sphaerulata (Conrad 1842) [=Pleurotomaria sphaerulata]KC60
|--T. kansuensisG31
`--T. tumidaG31
*Type species of generic name indicated
References
[BR05] Bouchet, P., & J.-P. Rocroi. 2005. Classification and nomenclator of gastropod families. Malacologia 47 (1–2): 1–397.
[BR17] Bouchet, P., J.-P. Rocroi, B. Hausdorf, A. Kaim, Y. Kano, A. Nützel, P. Parkhaev, M. Schrödl & E. E. Strong. 2017. Revised classification, nomenclator and typification of gastropod and monoplacophoran families. Malacologia 61 (1–2): 1–526.
[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.
[KC60] Knight, J. B., L. R. Cox, A. M. Keen, R. L. Batten, E. L. Yochelson & R. Robertson. 1960. Gastropoda: systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt I. Mollusca 1: Mollusca—General Features, Scaphopoda, Amphineura, Monoplacophora, Gastropoda—General Features, Archaeogastropoda and some (mainly Paleozoic) Caenogastropoda and Opisthobranchia pp. I169–I331. Geological Society of America, and University of Kansas Press.
[RFD04] Rohr, D. M., M. F. Fix & G. Darrough. 2004. Life association of shell and operculum of Ceratopea Ulrich, 1911 (Ordovician; Gastropoda). Journal of Paleontology 78 (1): 218–220.
[TTE93] Tracey, S., J. A. Todd & D. H. Erwin. 1993. Mollusca: Gastropoda. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 131–167. Chapman & Hall: London.
[W77] White, C. A. 1877. Report upon the invertebrate fossils collected in portions of Nevada, Utah, Colorado, New Mexico, and Arizona, by parties of the expeditions of 1871, 1872, 1873, and 1874. U.S. Geographical Surveys West of the One Hundredth Meridian 4 (1): 1–219, pls 1–21.
[X97] Xi Y.-H. 1997. Gastropods from Fentou Formation of Jiangsu and Anhui provinces. Acta Palaeontologica Sinica 36 (2): 238–244.
[YN83] Yu W. & Ning H. 1983. Middle Ordovician gastropods from Ruoqiang, Xinjiang. Acta Palaeontologica Sinica 22 (2): 199–203.
[YX95] Yu W. & Xi Y.-H. 1995. Ordovician-Devonian gastropods from Bachu and Kalpin districts, Xinjiang. Acta Palaeontologica Sinica 34 (4): 488–494.