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出典:『Wikipedia』 (2011/06/29 14:08 UTC 版)

英語による解説

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Hybodus ("humped tooth") is an extinct genus of once-common, widespread and long lived sharks, first appearing towards the end of the Permian period, and disappearing at the beginning of the Cretaceous. During the Triassic, Jurassic, and Cretaceous periods the hybodonts were especially successful and could be found in shallow seas across the world. For reasons that are not fully understood, the hybodonts became extinct near the end of the Cretaceous period.