Dimetrodon, the Solar-Powered, Sail-Backed Scourge Before the Dinosaurs

Image courtesy of Dmitry Bogdanov.

Even among mass extinctions, the Permian-Triassic extinction event is a stunner. It was the most cataclysmic evolutionary massacre of all time, truly deserving of its maudlin nickname, “the Great Dying.” Over 70 percent of marine life was killed, and a whopping 90 percent of terrestrial life was thrown onto the genetic trash heap. Mother Earth can really be a psychopath sometimes.

One of the most tragic victims of the Great Dying was the Dimetrodon, a synapsid reptile that rocked a gorgeous, multipurpose solar panel on its spine. Its pluckier relative, the Lystrosaurus, managed to survive the ordeal, and ended up having Pangaea practically to itself for millions of years. But whatever evolutionary game Dimetrodon lacked when compared to its cousin, it's made up for by being the infamous scourge of the early swamplands. The Lystrosaurus may have been a survivor, but Dimetrodon, with its bizarre body plan and influential pedigree, is the undisputed poster predator of the Permian period.

Image courtesy of Dmitry Bogdanov.

The genus began to thrive around 290 million years ago, during a period that really should be called “the Great Drying.” After the slow demise of the rich Carboniferous rainforests, Pangaea had began to develop arid regions and large deserts, which greatly benefited reptiles over amphibians. Dimetrodon took full advantage of the opportunity, and rose to become a top predator in marshy areas.

The size of the animal ranged greatly depending on the species, from the 15-foot-long D. angelensis to the 24-inch D. teutonis. But every variety of Dimetrodon had one thing in common: the unique spinal sail. It was a feature that wouldn't be seen on an animal again until the Cretaceous mega-monster Spinosaurus sprouted one.

Image courtesy of AMNH

There is a lot of debate about what roles the sail played, but it's widely accepted that it was, at the very least, a solar panel that sped up the process of charging Dimetrodon's cold-blooded batteries. The rapid growth of the sail as the animal evolved suggests that sexual selection of larger sails was a major factor in its development. Either the size of the spinal frill was sexy in itself, or it represented the individual's ability to generate more energy. Whatever the reason, large-sailed Dimetrodons got laid a lot over the genus' 30 million year reign on the planet.

The Dimetrodon is frequently mistaken for being a dinosaur, despite the fact that it preceded the rise of the Mesozoic monsters by at least 50 million years. In fact, Dimetrodon is much more closely related to mammals than it is to dinosaurs, though it is not the direct ancestor of any mammalian line. Even so, its proto-mammalian cranial features make it one of the more appealing contenders for humanity's coolest great-grand-uncle.

Given the imperative to switch to renewable energy sources like solar power in order to thwart our own self-imposed extinction, there's never been a better time to cherish the legacy of the Dimetrodon—the most impressive walking solar panel that ever roamed the Earth.