Extinct species

Dimetrodon

Dimetrodon grandis (Case, 1907)

Taxonomy

Range: Texas and Oklahoma, North America
Habitat: Terrestrial Permian lowlands, including floodplains and seasonally wet inland environments.
Lived: Early Permian · about 286–274 million years ago

Classification: Though it's often mistaken for a dinosaur in pop culture, this animal belongs to a much older lineage that is more closely related to mammals than to any reptile or dinosaur.
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Trait: It was the largest known species within its own genus, and its teeth show the oldest confirmed example in the fossil record of true serrated, saw-edged enamel built over an internal dentine core.
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Size: Adults are estimated to have weighed in the range of 200 to 300 kilograms, reaching lengths of roughly 4.5 meters.
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Habitat: It lived on seasonally dry floodplains crossed by shifting river channels, in the reddish mudstone and sandstone deposits typical of the early Permian interior of North America.
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Distribution: Fossils attributed to this species have been recovered from red-bed deposits in both Texas and Oklahoma.
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Time Context: It lived tens of millions of years before the first dinosaurs appeared, during an earlier chapter of life on land.
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