在进化中，头索动物文昌鱼被认为是接近于脊椎动物的活化石。

In evolution, Amphioxus, a cephalochordate, has been regarded as the living fossil closest to the vertebrates.

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在进化中，头索动物文昌鱼被认为是接近于脊椎动物的活化石。

In evolution, Amphioxus, a cephalochordate, has been regarded as the living fossil closest to the vertebrates.

youdao