Potamididae, common name potamidids (also known as horn snails or mudwhelks) are a family of small to large brackish water snails that live on mud flats, mangroves and similar habitats. They are amphibious gastropod molluscs in the superfamily Cerithioidea.

Traditionally, potamidids and batillariids have been confused because they have similar shells and they live in similar environments. For many fossil taxa the family assignment to either of these two families is still unresolved or controversial.

According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Potamididae has no subfamilies.

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