Pododesmus patelliformis, the ribbed saddle-oyster, is a species of bivalve mollusc in the family Anomiidae.

This oyster has a thin asymmetric shell up to four centimetres in length which is white, sometimes with brown markings.

The outline is roughly circular and the beaks are central but set back from the margin.

[2][3][4] This species occurs on the north west fringes of Europe extending from Norway to the Mediterranean Sea.

It lives on coarse sand and gravel, attached to rocks or other shells by its byssus.