Cephalopods may have evolved complex brains long before our vertebrate relatives.

头足或许比我们的脊近亲更早演化出复杂的脑部。

In early fish-like vertebrates more than 500 million years ago; in a common ancestor of arthropods, such as insects, spiders, and crustaceans, at around the same time; and then in the cephalopod mollusks around 300 million years ago.

在 5 亿多年前的早期鱼脊中；节肢的共同先，如昆虫、蜘蛛和甲，大约在同一时期；然后是 3 亿年前的头足软体。

You see, being different from other members of the cephalopod group is in fact an advantage for the vampire squid.

你看，与头足的其他成员不同实际上是吸血鬼鱿鱼的一个优势。

But in the Devonian, a new branch of the cephalopod family tree appeared: ammonites.

但在泥盆纪，出现了头足 家族树的一个新分支：菊石。

We're quite lucky, in that ammonites belong to the large group of mollusks called the cephalopods.

我们很幸运，因为菊石属于被称为头足的一大软体。