Isospiridae is an extinct family of fossil sea snails, Paleozoic gastropod mollusks.
This family is unassigned to superfamily. This family has no subfamilies according to the taxonomy by Bouchet & Rocroi (2005). It is classified as "Basal taxa that are certainly Gastropoda" by Bouchet & Rocroi (2005).
Genera
Isospira Koken, 1897 - type genus of the family Isospiridae. Species include: Isospira bucanioides Koken, 1897 Isospira huttoni Cowper Reed, 1921 Isospira lepida Perner, 1903 Isospira nautilina Koken & Perner, 1925 Isospira reinwaldti Öpik, 1930 Isospira reticulatus Wängberg-Eriksson, 1964 - synonym: Isospira reticulata
Taxonomy
Peter J. Wagner consider Isospiridae as synonym of Cyrtonellidae within Tergomya, The Paleobiology Database has become adatapted to this unpublished opinion by Wagner. This alternate taxonomy is as: Tergomya, Cyrtonellida, Cyrtonellidae.