奥陶纪

àotáojì

the Ordovician Period

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Ordovician; Ordovician period

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Ordovician period

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Ao4 tao2 ji4

Ordovician (geological period 495-440m years ago)

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奧陶紀|奥陶纪 [Aò táo jì] ► Ordovician (geological period 495-440m years ago)