Dimetrodon fossil map
Where fossils of Dimetrodon have been found, shown on the Earth as it looked about 275 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 275 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Pre-mammals (synapsids) |
|---|---|
| Lived | 298.9–266.9 million years ago (Asselian to Roadian) |
| Periods | Permian |
| Family | Sphenacodontidae |
| Named by | Cope 1878 |
| Fossil records | 94 occurrences at 60 locations (PBDB) |
| Found in | United States, Canada, Germany |
| Rock formations | Vale, Arroyo, Belle Plains, Waggoner Ranch, Admiral, Garber |
About Dimetrodon
Dimetrodon ( or; lit. 'two measures of teeth') is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian to early Guadalupian epoch of the Permian period, around 294.1–271 million years ago. With most species measuring 1.7–4.6 m (5.6–15.1 ft) long and weighing 28–250 kg (62–551 lb), the most prominent feature of Dimetrodon is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It was an obligate quadruped (it could walk only on four legs) and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority of these coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have also been found in Germany and over a dozen species have been named since the genus was first erected in 1878.
Text in “About” is quoted from the Wikipedia article Dimetrodon (revision 1380037660), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q130869.
