Editing Dimetrodon (section)

==== Teeth ====
The size of the teeth varies greatly along the length of the jaws, lending ''Dimetrodon'' its name, which means "two measures of tooth" in reference to sets of small and large teeth.<ref name=AMNH>{{cite web|url=http://www.amnh.org/exhibitions/permanent/fossilhalls/vertebrate/specimens/dimetrodon.php |title=Exhibit Specimens: Dimetrodon |work=American Museum of Natural History |access-date=2 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120704182723/http://www.amnh.org/exhibitions/permanent/fossilhalls/vertebrate/specimens/dimetrodon.php |archive-date=4 July 2012 }}</ref> One or two pairs of caniniforms (large, pointed, [[Canine tooth|canine]]-like teeth) extend from the maxilla. Large incisor teeth are also present at the tips of the upper and lower jaws, rooted in the premaxillae and [[dentary bone]]s. Small teeth are present around the maxillary "step" and behind the caniforms, becoming smaller further back in the jaw.<ref name=BC99>{{cite journal |last=Baur |first=G. |author2=Case, E.C. |year=1899 |title=The history of the Pelycosauria, with a description of the genus ''Dimetrodon'', Cope |journal=Transactions of the American Philosophical Society |volume=20 |issue=1 |pages=5–62 |jstor=1005488|doi=10.2307/1005488 |hdl=2027/uc1.32106020416696 |hdl-access=free }}</ref>

[[File:Dimetrodon grandis Exhibit Museum of Natural History.JPG|thumb|left|A skull of ''D.&nbsp;grandis'']]

Many teeth are widest at their midsections and narrow closer to the jaws, giving them the appearance of a teardrop. Teardrop-shaped teeth are unique to ''Dimetrodon'' and other closely related [[sphenacodontid]]s, which helps to distinguish them from other early synapsids.<ref name=FSMSS11 /> As in many other early [[synapsid]]s, the teeth of most ''Dimetrodon'' species are serrated at their edges.<ref name=FSMSS11 /> The serrations of ''Dimetrodon'' teeth were so fine that they resembled tiny cracks.<ref name="alberto-tooth-abs-84">Abler, W.L. 2001. A kerf-and-drill model of tyrannosaur tooth serrations. p.&nbsp;84-89. In: ''Mesozoic Vertebrate Life''. Ed.s Tanke, D. H., Carpenter, K., Skrepnick, M. W. Indiana University Press.</ref> The dinosaur ''[[Albertosaurus]]'' had similarly crack-like serrations, but, at the base of each serration was a round [[Vacuum|void]], which would have functioned to distribute force over a larger [[surface area]] and prevent the stresses of feeding from causing the crack to spread through the tooth. Unlike ''Albertosaurus'', ''Dimetrodon'' teeth lacked adaptations that would stop cracks from forming at their serrations.<ref name="alberto-tooth-abs-84" /> The teeth of ''D.&nbsp;teutonis'' lack serrations, but still have sharp edges.<ref name=FSMSS11 />

A 2014 study shows that ''Dimetrodon'' was in an arms race against its prey. The smaller species, ''D. milleri'', had no tooth serrations because it ate small prey. As prey grew larger, several ''Dimetrodon'' species started developing serrations on their teeth and increasing in size. For instance, ''D. limbatus'' had enamel serrations that helped it cut through flesh (which were similar to the serrations that can be found on ''[[Secodontosaurus]]''). The second-largest species, ''D. grandis'', has denticle serrations similar to those of sharks and [[Theropoda|theropod]] dinosaurs, making its teeth even more specialized for slicing through flesh. As ''Dimetrodon'''s prey grew larger, the various species responded by growing to larger sizes and developing ever-sharper teeth.<ref>{{Cite web|url=https://www.nationalgeographic.com/environment/topic/great-energy-challenge|title=Great Energy Challenge|website=Environment}}</ref> The thickness and mass of the teeth of ''Dimetrodon'' may also have been an adaptation for increasing dental longevity.<ref>{{cite journal |last1=Maho |first1=Tea |last2=Maho |first2=Sigi |last3=Scott |first3=Dianne |last4=Reisz |first4=Robert R. |date=19 August 2022 |title=Permian hypercarnivore suggests dental complexity among early amniotes |journal=[[Nature Communications]] |volume=13 |issue=1 |page=4882 |doi=10.1038/s41467-022-32621-5 |pmid=35986022 |pmc=9391490 |bibcode=2022NatCo..13.4882M }}</ref>