See text Ancylus is a genus of very small, freshwater, air-breathing limpets.

They are aquatic pulmonate gastropod mollusks in the tribe Ancylini within the family Planorbidae, the ram's horn snails and their allies.

[2] The genus is known throughout the Cenozoic.

[3] Species in the genus Ancylus include: A cladogram based on sequences of mitochondrial 16S ribosomal RNA and cytochrome-c oxidase I (COI) genes showing phylogenic relations of Ancylus by Albrecht et al. (2006):[6] Ancylus sp.

C Ancylus sp.