Page 47 - Prehistoric Animals

Die-Metro-Don

Dimetrodon

Dimetrodon* (two measures of teeth) is a genus of non-mammalian synapsid that lived in
the Early Permian period, around 295–272 million years ago**. Although their size and weight
varied across the species the largest was around 2 to 5 metres and are estimated to have weighed
between 28 and 250 kg. The smallest known species D.eutonis was about 60 cm long and
weighed 14 kilograms. It is, however, believed the larger of the species were among the largest
predators of its time.

The most notable feature of Dimetrodon is the large semi-circular structure protruding from
it back. Since its naming by Edward Drinker Cope in, 1878, this structure has been a bit of a puz-
zle. Some say it was used to lure a mate; others, that it was used for ventilation. Some say it was
used for both.

The skull of Dimetrodon was narrow but robust. Its jaws housed two sets of teeth. Hence the
name meaning, two measures of teeth. It had large front incisors which would be used for grip-
ping its prey and smaller sharp chewing teeth at the back. As a carnivore, Dimetrodon was a very
successful predator. This success is confirmed by the fossil records and there distribution; they
are found widespread across both the Americas and Europe and span across a very long time pe-
riod.

Dimetrodon was a member of a group known as pelycosaurs, this group predated dinosaurs
by millions of years. Pelycosaurs are believed to have gone extinct sometime towards the end of
the Permian, some 230 million years ago.

*Dimetrodon, was not a dinosaur, it roamed the planet about 40 million years before the first dinosaur’s appeared.
**Although many of the best fossil finds are in North America, Dimetrodon roamed on a very different world. At that time the world
was just one giant continent; Pangaea.