Nucula is a genus of very small saltwater clams.

Fossils are known from the Arenig to the Quaternary (age range: from 478.6 to 0.0 million years ago).

[1] Shells of species within this genus can reach a size of about 30 millimetres (1.2 in).

These clams live in the muddy sand close to the sediment surface at a depth of 20 to 200 meters.

[2] Nowadays there are still many species of this genus, which have had virtually no change in the course of time.