The family first appeared during the Middle Triassic[1] and disappeared during the Late Cretaceous.

The group has been found in rock formations in Africa, Australia, Eurasia and North America.

[2] As ginglymodians, their closest living relatives are gars, with them being typically placed as nested within the Semionotiformes.

[3] Many members of the family have elongated dorsal fins, often associated with adjacent area of skin which was free of scales.

Their body morphology suggests that they were slow swimmers that were capable of maneuvering around complex topography, such as reef environments.