Dimetrodon - (pronounced die-MET-roh-don)

Dimetrodon (meaning: two measures of teeth), was a predatory synapsid ('mammal-like reptile') genus that flourished during the Permian Period (before dinosaurs evolved) and was a carnivore. It probably ate other pelycosaurs (its close relatives), insects and other animals.

 

It lived between 280 and 265 million years ago. It was more closely related to mammals than to true reptiles (Sauropsida), such as dinosaurs, lizards and birds. Dimetrodon was not a dinosaur, despite being popularly grouped with them. It is correctly classified as a 'pelycosaur' (primitive Late Paleozoic synapsid amniotes and relatives of warm-blooded mammals).

Dimetrodon was an apex predator (predators that, as adults, are not normally preyed upon in the wild in significant parts of their ranges), and was among the largest of its day. Dimetrodon grew to up to 3 metres (9.8 feet) in length and weighed roughly 550 pounds (250 kg). It had a large spiny sail along its back which was a flap of skin dense with blood vessels and walked on four side-sprawling legs, it may have moved in a manner similar to present-day lizards. The sail was supported by long, bony spines, each of which grew out of a separate spinal vertebra (a bone in the back). The sail may have been a thermoregulatory structure, used to absorb and release heat. The sail may have also been used for mating and dominance rituals and for making it look much larger than it was to ward off potential predators.

The term 'two measures of teeth' refer to the fact that it had a large skull with two different types of teeth (shearing teeth and sharp canine teeth), unlike reptiles.

Dimetrodon was a dominant carnivore during the Permian period, living mainly in swampy areas. Unlike their fellow non-finned pelycosaurs, they warmed up early after sunrise and cooled off more efficiently during the heat of the day. This efficient thermoregulation along with their large and powerful jaws gave them the advantage making them dominant over their fellow creatures. They were probably very fast runners.

Fossils of Dimetrodon have been found in North America and Europe. The climate of Europe and North America in the Early Permian, was probably arid to continental, so Dimetrodon was probably adaptable. Trackways (fossilized footprints) of Dimetrodon have been found in Nova Scotia, Canada. Dimetrodon was named by paleontologist Edward Drinker Cope.

Dimetrodon went extinct in the huge Permian extinction, 245 million years ago, which immediately preceded the Mesozoic Era.

Scientific Classification:

Kingdom: Animalia

Phylum: Chordata

Class: Synapsida

Order: Pelycosauria

Family: Sphenacodontidae

Genus: Dimetrodon