Diplocaulidae

Diplocaulus (meaning "double stalk") is an extinct genus of lepospondyl amphibians which lived from the Late Carboniferous to the Late Permian of North America and Africa. Diplocaulus is by far the largest and best-known of the lepospondyls, characterized by a distinctive boomerang-shaped skull. Remains attributed to Diplocaulus have been found from the Late Permian of Morocco and represent the youngest-known occurrence of a lepospondyl.

Diploceraspis is an extinct genus of diplocaulid nectrideans. It lived in North America during the Permian period. It closely resembles its relative, Diplocaulus. It generally sports the same features as Diplocaulus, though it was smaller, measuring over 46 cm. Beerbower originally recognised two species, D. burkei and D. conemaughensis, but they are no longer regarded as being distinct from one another as their size ranges were found to overlap. Other species include D. meritae from Nebraska and an indeterminate species from Oklahoma. Diplocaulus minimus of Late Permian Morocco may be of

Keraterpeton is an extinct genus of "nectridean" tetrapodomorphs, previously included within the monotypic Keraterpedontidae family, from the Carboniferous period of Europe (Czech Republic, England and Ireland) and North America (United States); it is the oldest known member of the family Diplocaulidae.

Batrachiderpeton is an extinct genus of nectridean tetrapodomorphs within the family Diplocaulidae; it was a basal member of the family. The type species is B. reticulatum and was found in a coal field in Northumberland, England at a locality that also yields the remains of Anthracosaurus russelli. A second species is also known: B. lineatum.

The Diplocaulidae ("double cauls") is an extinct family of "nectridean" tetrapodomorphs that arose during the Late Carboniferous and died out in the Late Permian. They are distinguished by the presence of strange, horn-like protrusions jutting out from the rear of their skulls; in some genera said protrusions gave their heads an almost boomerang-like outline. thumb|left|Diploceraspis burkei

Diceratosaurus is an extinct genus of nectridean tetrapodomorphs within the family Diplocaulidae. Fossils of Diceratosaurus were first described by Edward Drinker Cope in 1874. The species D. brevirostris is well known from Jefferson County, Ohio, with approximately 50 specimens having been collected from the Ohio Diamond Coal Mine. The mine was situated in the village of Linton, which became obscure soon after operations were completed and the mine closed in 1921. Diceratosaurus brevirostris dates back to the Mascovian period, 370 years ago.