Kingdom Animalia
Phylum Chordata
Superclass Tetrapoda
Class  ???
Order Pelycosauria
Family Sphenacodontidae
Subfamily Sphenacodontinae
Genus Dimetrodon
1st Species Dimetrodon limbatus
2nd Species Dimetrodon borealis
3rd Species Dimetrodon grandis
4th Species Dimetrodon natalis
Other attributes
Time Range 295-272 mya
Location United States of America, Germany
Name Meaning Two measures of teeth
Physical Dimensions 2.8 meters long for D.grandis; 4 meters long for D.angelensis; 50 centimeters long for D.teutonis
Dietary Classification Carnivore
Dimetrodon is a sphenacodontid pelycosaur synapsid from the Cisuralian-Guadalupian of the United States of America and Germany. It was officially named in 1878 by Edward Drinker Cope. It is the most famous synapsid to exist, and is also one of the most studied.


Dimetrodon had the generic pelycosaur synapsid build, with 4 legs, a moderately long tail, a somewhat slender body, and a big head with large jaws. However, it had one major difference; it had a large sail on its back. Its body would have been covered in scaly skin.


Dimetrodon was a predator, preying on sharks, small amphibians, small reptiles, and in some cases, insects. Its jaws had two kinds of teeth, hence the meaning of its name, "two measures of teeth"; at the front of its jaws, it had large, serrated teeth designed for slicing flesh, while at the back of its jaws, it had smaller teeth designed for grabbing prey.


In a similar case to Edaphosaurus's sail, the function of Dimetrodon's sail remains open to debate. The prevalent theory at the time was that it used its sail to regulate its body temperature; however, thanks to a(n immediately disproven) study that said that it had a set of bony prongs rather than a proper sail, the most widely accepted theory is that it possibly was just used for display. However, it's certain that it was a successful predator, as its two teeth were very useful for eating; its smaller back teeth were used for getting a grip of slippery prey such as Xenacanthus and Diplocaulus, while its bigger front teeth were used for cutting into their flesh. As well as this, it is unknown whether Dimetrodon was a terrestrial or amphibious predator; however, chemical traces on its bones suggests that it was the former, feeding on land and near the riverbanks.

In popular cultureEdit

Dimetrodon was first introduced to the public in the Rite of Spring segment of the 1940 Disney musical movie, Fantasia. Since then, it has been featured in major pieces of media like The Land Before Time and the 1959 adaptation of Journey to the Center of the Earth, where it is inaccurately featured as an archosaurian reptile that lived alongside dinosaurs such as Stegosaurus, Triceratops, Pteranodon (which is actually not a dinosaur, but is listed as one), and Tyrannosaurus; it was even planned to be in Jurassic World before it got cut. So far, Dimetrodon's biggest appearance was in the 2nd episode of the 2005 documentary Walking with Monsters, where it is shown as a terrestrial predator able to eat other synapsids such as Edaphosaurus, as well as a caring (albeit cannibalistic) mother; at the end of the segment, it evolves into Inostrancevia over a course of 26 million years.

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