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Dimetrodon grandis is a geologically widespread species of synapsid that lived in the Early Permian, between 295-272 million years ago. Though D. grandis bears a superficial resemblance to dinosaurs, it is more closely related to mammals and became extinct 60 million years before the first dinosaurs appeared in the fossil record (1).
D. grandis is considered an apex predator in Early Permian ecology. It was one of the first large-bodied terrestrial predators to evolve and had a maximum length of 5 meters (2, 3). It preyed upon a variety of taxa, including fish, and amphibians. The most prominent feature of D. grandis is the large sail on its back, formed from elongated spinal vertebrae and prompting years of scientific debate as to the function of the feature (4, 5).