Diplocaulus

Diplocaulus Temporal range: 299–251 Ma PreЄ Є O S D C P T J K Pg N Early to Late Permian
Diplocaulus magnicornus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	"Amphibia" (wide sense)
Subclass:	†Lepospondyli
Order:	†Nectridea
Family:	†Diplocaulidae
Genus:	†Diplocaulus Cope, 1877
Species
†D. salamandroides Cope, 1877(type) †D. magnicornis Cope, 1882 ?†D. brevirostris Olson, 1951 ?†D. recurvatus Olson, 1952 ?†D. minimus Dutuit, 1988
Synonyms
Genus-level: Permoplatyops Case, 1946 Species-level: Diplocaulus limbatus Cope, 1895 Diplocaulus copei Broili, 1902 Diplocaulus pusillus Broili, 1904 Permoplatyops parvus (Williston, 1918 [originally Platyops parvus]) Diplocaulus parvus Olson, 1972

Diplocaulus (meaning "double caul") is an extinct genus of lepospondyl amphibians from the Permian period of North America. It is one of the largest lepospondyls, with 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.

Description

Diplocaulus had a stocky, salamander-like body, but was relatively large, reaching up to 1 m (3.3 ft) in length. Its most distinctive features were the long protrusions on the sides of its skull, giving the head a boomerang shape.^[1] Judging from its weak limbs and relatively short tail, it is presumed to have swum with an up-and-down movement of its body, similar to modern whales and dolphins. The wide head could have acted like a hydrofoil, helping the creature glide through the water. Another possibility is that the shape was defensive, since even a large predator would have a hard time trying to swallow a creature with such a wide head.^[2] Rare trace fossils of Diplocaulus-like amphibians show that the tips of the boomerang-shaped head were connected to the body by flaps of skin.^[3][4]

A close relative of Diplocaulus is Diploceraspis.

Diplocaulus on display

• The fossilized skeleton of a Diplocaulus is on display at the University of Michigan Museum of Natural History in Ann Arbor. The display presents art of the Diplocaulus with the controversial skin extending from the tips of the head to the tail.
• The fossilized skeleton of a Diplocaulus is on display at the Houston Museum of Natural Science in Houston.

Gallery

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  Skull of Diplocaulus magnicornis at the Museum für Naturkunde Berlin

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References

1. Cruickshank, A. R. I.; Skews, B. W. (1980). "The Functional Significance of Nectridean Tabular Horns (Amphibia: Lepospondyli)". Proceedings of the Royal Society B: Biological Sciences 209 (1177): 513–537. doi:10.1098/rspb.1980.0110.
2. Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 55. ISBN 1-84028-152-9.
3. von Walter, H.; R. Werneberg (1988). "Über liegespuren (Cubichnia) aquatischer Tetrapoden (Diplocauliden, Nectridea) aus den Rotteroder Schichten (Rotliegendes, Thüringer Wald/DDR)". Freiberger Forschungshefte (Leipzig) C419: 96–106.
4. Wright, J. L.; I. J. Samson (1998). "The earliest known terrestrial tetrapod skin impressions (Upper Carboniferous, Shropshire, UK)". Journal of Vertebrate Paleontology. 18 (suppl.): 88A.