He also uses them for one of the most intimidating displays in nature... 还用颌来展现令人生畏的实力
Today, there are more than 30,000 species of fish. 今天存在超过三万种鱼
The pairing of backbones with jaws was to prove a winning combination. 颌搭配脊椎是胜利的组合
But the ammonoids boast a trick of their own... 但是菊石也有自己的本领
close relatives of today's deep-sea nautilus. 今天深海鹦鹉螺的近亲
a descendant of the tiny Arandaspis. 是微小的阿兰达甲鱼的后代
there was to be a changing of the guard. 即将发生权力转移
he's come to the shallows in search of a mate. 它来到浅海求偶
Off the coast of modern-day Australia, 在今天的澳大利亚海岸边
glaciers hundreds of meters tall cascaded into the warming seas. 高达数百米的冰川 倾泻进入正在变暖的海洋