Dimetrodon was a genus of nonmammalian synapsid from the early Permian period, occurring from around 295-272 million years ago. Oft-misidentified as a dinosaur, Dimetrodon was more closely related to mammals than reptiles, forbearing several key anatomical and physiological traits which would appear in its later mammalian relatives. Dimetrodon was notable for possessing a large dorsal sail comprised of elongated neural spines, the function of which is still debated. Paleontologist suggest the sail may have served to maintain thermoregulation, but other hypotheses propose sexual display for courtship, camouflage and locomotive stability. Dimetrodon species were numerous and various in size and ecology, the largest being apex predators of their ecosystems, like D. grandis, reaching up to 4 meters (13 feet), while the smallest, such as D. teutonis, only grew to 60 centimeters (24 inches). The largest species primarily preyed on a variety of land-based and freshwater organisms inhabiting the wetland environments of the early Permian, such as the herbivorous synapsid Edaphosaurus, reptiliomorph Diadectes, lepospondyl Diplocaulus, and freshwater shark Xenacanthus. Throughout its temporal range, Dimetrodon experienced an evolutionary arms race against its prey, as the early Permian saw the first truly large herbivores to evolve on land. Dimetrodon species adapted to the pressure of larger herbivores by growing larger over time, smaller species notably lacking the serrations seen in the teeth of larger species.
Fantasia (1940)[]
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Unknown Island (1948)[]
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Journey To The Center Of The Earth (1959)[]
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Valley of the Dinosaurs (1974)[]
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The Land Before Time (1988)[]
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Dinosaurs TV Series (1991-1994)[]
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Paleoworld (1994-1997)[]
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Trilogy of Life (1999-2005)[]
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Dinotopia: Quest for the Ruby Sunstone[]
Power Rangers: Dino Thunder (2004)[]
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Dinosaur Train (2013-2020)[]
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Toy Story That Time Forgot (2014)[]
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Dinotrux (2016-2017)[]
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Ancient Earth (2018)[]
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Jurassic World: Dominion (2022)[]
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