Bakevelliidae

See text Bakevelliidae is an extinct family of prehistoric bivalves that lived from the Late Mississippian until the Middle Eocene.

Living a stationary life attached to substrate in marine and brackish environments, they formed shells of an aragonite composition with a low amount of magnesium calcite.

Several of the species have an early growth period in which the valve ligament is anchored in a single pit in the shell.

When the species size exceeded approximately 6 millimetres (0.24 in) the ligament attachment would develop to encompass two or more pits.

One possible species of Bakevelliid from the early Triassic of Utah is tentatively included in the genus Bakevellia but is noted for having an adult shell with only one ligament attachment pit, contrary to the normal state of the rest of the family.