 A study in 2014 shows that Dimetrodon was in an arms race against its prey . The smaller species , D.milleri had no serrations since it ate small prey . As the prey grew larger , Dimetrodon started developing serrations and increasing in size . D.limbatus had enamel serrations that help it cut through flesh , and the same serrations can be found on Secodontosaurus . The second largest dimetrodon species , D.grandis , has denticle serrations similar to sharks and theropod dinosaurs , making its teeth even more specialized to slice through flesh . This study not only shows the evolution of Dimetrodon over millions of years , but also shows that Dimetrodon was in an arms race against its prey . As prey grew larger , Dimetrodon countered it by growing larger and having sharper teeth . 
