Skeleton assembly of D. incisivus in the State Museum of Natural History Karlsruhe

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Dimetrodon ( " two measures of teeth " ) is a genus of carnivorous Pelycosaurier ( Pelycosauria ), a paraphyletic taxon extinct synapsids ( formerly known as " mammal -like reptiles ") that from the early Permian. The name derives from the presence of two differently shaped tooth types. From the Pelycosauriern therapsides ( Therapsida ) emerged, of which mammals ( Mammalia) are derived. The American zoologist Edward Drinker Cope proposed the genus in 1878. The included tail up to 3.5 meters long animal lived about 299 to 272.5 million years ago in Cisuralium (early Permian) and was a carnivore.


Dimetrodon had a long tail, claws on its feet and moved on four legs ( quadruped ) away and could have weighed about 250 kg. A striking feature was probably over -stressed skin from prolonged spinous processes of the vertebrae of the torso and spine formed, large back sail that served the older text opinion probably to regulate body temperature and was trained by some other Pelycosauriern such as Edaphosaurus. To warm the body quickly, Dimetrodon probably turned the sun to the edge, making the cold-blooded ( poikilothermic ) animals could be more active. To cool off, he turned his body in parallel to the incident solar radiation.

This theory says that diemetradons close relative Sphenacodon trained not sail back, but only a low dorsal crest, which was unsuitable for thermoregulation.


Fossils of Dimetrodon have been found in the U.S. states of Texas and Oklahoma as well as in Europe. Very well preserved specimens of D. teutonis come from the Bromacker locality in Thuringia. Bromacker is an important locality for fossil land vertebrates ( Tetrapoda ) of the early Permian. Besides Dimetrodon also very good fossils of Diadectes and Seymouria were recovered, among others.

Described species

  • D. Olson angelensis
  • D. dollovianus ( Cope, 1888)
  • D. gigas ( Cope, 1878)
  • D. gigashomogenes Case
  • D. grandis ( Case, 1907)
  • D. incisivus Cope, 1878
  • D. longiramus Case, 1907
  • D. macrospondylus ( Cope, 1885)
  • D. natalis ( Cope, 1878)
  • D. obtusidens ( Cope, 1880)
  • D. occidentalis Berman, 1977
  • D. platycentrus Case, 1907
  • D. rectiformis Cope, 1878
  • D. semiradicatus Cope, 1881
  • D. teutonis Berman et al. 2,001

D. grandis

D. loomisi

D. milleri

D. angelensis