Fossil group

Megalodonts (bivalves)

Molluscs · Triassic – Jurassic

Thick-shelled marine bivalves of the Triassic–Jurassic (family Megalodontidae), often found in shallow-water limestones. They are molluscs, unrelated to the shark that shares the informal name.

A broad fossil group rather than a single taxon — the units below record it among their fauna or flora.