Rotulidae is a family of small sand dollars native to the Atlantic coast of Africa, with 3 genera, with Rotula and Heliophora being extant, the other, Rotuloidea, being extinct since the Pliocene, but all three being found in the fossil record along the Atlantic African coast since the Miocene.

While rotulids are very distinctive in appearance, they are also highly morphic, with a tremendous diversity seen in individual specimens.

Depending on the individual, indentations may be shallow or deep, and may be restricted to the posterior edge, or may be found along the entire margin of the test.

In the genus Rotula, the test has up to eleven indentations along the posterior edge, forming up to twelve digits.

The tests of this genus are extremely similar to those of Heliophora, especially of young specimens, sometimes to the point of confusion.