Late Cambrian – Middle Permian
Sinuitidae is a family of extinct epifaunal detritivores.
Description of the Family
- Anal emargination is generally a U-shaped sinus
- Rarely, in some advanced Euphemitinae, anal emargination narrows to broad slit
Treatise on Invertebrate Paleontology, Part I, Mollusca 1 (1960):
- Anal emargination mostly an open U-shaped sinus but narrowing to a broad slit in some advanced Euphemitinae