Plicatostylidae

Plicatostylidae is a family of extinct large-sized epifaunal marine to brackish bivalves that inhabited Europe, Asia, Africa and America during the Jurassic, though they survived until the Eocene. These groups are informally known as "Lithiotids" or "Lithiotid Bivalves". They represent large reef builders, analogues to the younger Rudists and modern Crassostrea, Magallana and less extent to Tridacna.