Pecten (Gigantopecten restitutensis)

Miocene Period. Vaucluse, Lacoste, France. This group of Gigantopecten lived in the shallow sea that covered part of France 3 million years ago. The immense size and thickness of shells indicate that these bivalve mollusks lived during a period of optimal habitat and resources. Groupings were important to the animals’ reproductive strategy. As broadcast spawners, individual scallops release eggs and sperm into the water simultaneously. Modern scallops are hermaphroditic, having both sets of reproductive organs. Individuals will change sex many times during their lives. Like modern scallops, ancient scallops may have been vulnerable to powerful storms that swept across their shallow habitats. Surging waves would have decimated populations, spreading individuals out too thinly to reproduce or, as with this fossil assemblage, burying them alive.