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

头足类或许比我们的脊椎动物近亲更早化出复杂的脑部。

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

我们很幸运，因为石属于被称为头足类的一大类软体动物。

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

你看，与头足类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，出现了头足类 家族树的一个新：石。

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 亿多年前的早期类鱼脊椎动物中；节肢动物的共同祖先，如昆虫、蜘蛛和甲壳类动物，大约在同一时期；然后是 3 亿年前的头足类软体动物。