Dimetrodon

Biology
Dimetrodon(two measures tooth) were carnivorous synapsid creature which lived Permian period(295 million ~ 272 million years). The reason why they called as two measures tooth, two different kinds or sizes of teeth in it's large skull. They were named by Edward Drinker Cope in 1884. Their fossils been found in Europe and USA, especially in Texas, Oklahoma in the U.S. At the first time, their sail looking spinal vertebrae connected with their skin were thought about as for regulate temperature, however they are also considered as communication or mating attraction.

History
There were many kinds of Dimetrodon(D. natalis, D. milleri, D. limbatus and D. grandis) contained in the zoo, however because of a lot of number of them, they devoured them each or perished because of starvation. Since that case, the zoo had no choice to separate the surviving species(2 male and 1 female D. natalis, 2 male D. limbatus and 1 male and 1 female D. grandis) for their remaining enclosures.