Scoliostomatidae

Various views of Pseudomitchellia macqueeni from Frýda et al. (2002).

Belongs within: Gastropoda.

The Scoliostomatidae are a Devonian family of gastropods with a distinctive shell morphology: at maturity, the last whorl of the shell twists outwards and backwards, so its apparent position is reversed relative to the rest of the shell.

See also: Snails letting it all hang out.

Characters (from Frýda et al. 2002): Small, dextrally coiled, moderately high-spired shells with final half-whorl twisting outwards and backwards; aperture faces backwards, opposite to usual direction (in apertural view being at left side); shells with or without sinus or slit generating selenizone.

<==Scoliostomatidae
    |--Mitchelliinae FBL02
    |    |--Mitchellia de Koninck 1877 FBL02
    |    |    `--*M. striatula Koninck 1877 FBL02
    |    `--Pseudomitchellia Frýda, Blodgett & Lenz 2002 FBL02
    |         |--*P. bohemica (Perner 1903) [=Scoliostoma bohemica] FBL02
    |         `--P. macqueeni Frýda, Blodgett & Lenz 2002 FBL02
    `--Scoliostomatinae FBL02
         |--Brilonella Kayser 1873 FBL02
         |--Scoliostoma Braun 1838 FBL02
         |    `--*S. dannenbergi Braun 1938 FBL02
         |--Anarconcha Horný 1964 FBL02
         |    `--A. pulchra (Perner 1903) FBL02
         `--Eoscoliostoma Frýda, Blodgett & Lenz 2002 FBL02
              `--*E. norrisi Frýda, Blodgett & Lenz 2002 FBL02

*Type species of generic name indicated

REFERENCES

[FBL02] Frýda, J., R. B. Blodgett & A. C. Lenz. 2002. New Early Devonian gastropods from the families Crassimarginatidae (new family) and Scoliostomatidae (new family), Royal Creek area, Yukon Territory, Canada. Journal of Paleontology 76 (2): 246-255.