[1] Most studies since this discovery have argued that anguiliform (eel-like) tail movement was the main force of locomotion utilized by Diplocaulus and its relatives.

[2][3] The most distinctive features of this genus and its closest relatives were a pair of long protrusions or horns at the rear of the skull, giving the head a boomerang-like shape.

In Urocordylus, the tabular lies closer to the back of the skull and even contacts the parietals, invalidating Olson's main point.

[9] The rocks in which these fossils were discovered had been informally referred to as the "Clepsydrops shales", named after a local genus of early synapsid by Cope in 1865.

The shales were initially believed to be from either the Permian or Triassic periods in age based on the purported presence of reptile and lungfish fossils.

D. magnicornis was the first species known from more than vertebrae, and it allowed Cope and other paleontologists to realize the nature of Diplocaulus as a bizarre long-horned "batrachian" (amphibian).

It is represented by a small number of specimens found in an early strata of the Texas red beds, specifically the Arroyo Formation of the Clear Fork Group.

In addition, the horns are more elongated, the parietals have a convex upper surface, and the rear edge of the skull is more strongly and smoothly curved.

Olson, the original describer of the species, suggested that it occupied different habitats than D. magnicornis such as mountain streams, accounting for its comparative rarity.

[4] Another hypothesis was provided in a dissertation, published by University of Kansas professor Herman Douthitt in 1917, which focused entirely on the anatomy of Diplocaulus.

Douthitt argued that the most undisputed function was that the horns acted as a counterweight to offset the heavily-built forward part of the head which would have been difficult to lift otherwise.

He also briefly proposed other possible functions, such as the use of the broad head as a burrowing tool to escape predators or survive droughts.

His argument relied on the possibility that the horns supported operculum-like vertical pouches protecting external or internal gills.

The model was placed in a wind tunnel, and subjected to several tests to determine drag, lift, and other forces experienced by the head in different situations.

[3] The results showed that the horns generated significant lift, which would have allowed the animal to rise in the water column of a river or stream quite quickly and easily.

[3] When the "mouth" of the model was opened, lift was barely affected, the pitching moment decreased, and drag only slightly increased.

Cruickshank & Skews also glued numerous small spheres to the model in order to test how an irregular texture would affect the mechanics of the head.

When the flange was removed from the smooth model, the resulting lift forces started being generated at a lower angle, 6 degrees below the horizontal rather than 1.5.

One of the three was killed with a bite to the head, taking part of its skull and portions of the brain, a fatal injury that the animal could not defend against.