1.7" Edaphosaurus (Permian Synapsid) Vertebrae - Texas

Edaphosaurus is an important fossil: it is one of the earliest known large plant-eating (herbivorous) amniote tetrapods (four-legged land-living vertebrates). In addition to the large tooth plates in its jaws, the most characteristic feature of Edaphosaurus is a sail on its back. A number of other synapsids from the same time period also have tall dorsal sails, most famously the large apex predator Dimetrodon. However, the sail on Edaphosaurus is different in shape and morphology: Dimetrodon's is straighter and comes to more of a point at the center, while

An artists reconstruction of Edaphosaurus. By Nobu Tamura, Creative Commons License