Edaphosaurus pogonias

Edaphosaurus was a plant-eating, Early Permian synapsid. Living in the same time and swampy environments as its carnivorous relative Dimetrodon, Edaphosaurus had an even stranger sail, which had little projections sticking sideways out of every elongated neural spine. Wind-tunnel tests suggest this would produce eddies of air in a breeze, causing convection currents that would aid in cooling down its body temperature.