泥盆纪末期是脊椎动物出现很的关键时期。

The end of the Devonian was a crucial time for vertebrates.

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自从泥盆纪以来就生存的低等维管植物。

Lower tracheophytes in existence since the devonian.

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自从泥盆纪以来就生存的低等维管植物。

Lower tracheophytes in existence since the devonian.

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