Their ancestors were these things called eurypterids, or sea scorpions, and they were huge.

它们的祖先是广翅目动物，或者叫海蝎子，它们体型巨大。

The waters teemed with squid, bony fish, and sea scorpions.

水域盛产鱿鱼、硬骨鱼和 海蝎。

Somewhere around China, a fish developed jaws, and its descendants drove jawless fishes, sea scorpions and branching plankton to extinction.

在中国的某个地方，一条鱼长出了颚，它的后代使无颚鱼、海蝎子和分支浮游生物灭绝。

So tough, in fact, that it needed skin made of teeth to protect itself from things like giant sea scorpions.

如此坚韧，事实上，它需要用牙齿制成的皮肤来保护自己免受巨型海蝎之类的伤害。

But, during the Late Ordovician, a second suborder of sea scorpion emerges in the fossil record — the Eurytperina.

但是，在晚奥陶世期间，化石记录中出现了海蝎的第二个亚目——Eurytperina。

Sea scorpions, meanwhile, retained their book-gills, which are similar to what horseshoe crabs use to breathe today.

与此同时， 海蝎子保留了它们的书鳃，这类似于今天鲎用来呼吸的东西。

Maybe if they'd developed a way to leave the water sooner, sea scorpions would still be around.

也许如果他们早点找到离开水的方法，海蝎子就会仍然存在。

They were some of the only sea scorpions to cross the open ocean, exploring the seas between the continents of Euramerica and Gondwana.

它们是仅有的一些穿越公海、探索欧美大陆和冈瓦纳大陆之间海域的海蝎子。

The culprit was an apex predator that dominated the seas of the late Silurian and early Devonian: the sea scorpion.

罪魁祸首是一种顶级捕食者，它在志留纪晚期和泥盆纪早期的海洋中占主导地位：海蝎子。

Because of these features, some researchers believe that kiemenplatten allowed sea scorpions to mate and lay their eggs on land, or even to develop an amphibious lifestyle.

由于这些特征， 一些研究人员认为 kiemenplatten 允许海蝎子在陆地上交配和产卵，甚至发展出两栖的生活方式。

Sea scorpions would soon come to be defined by how they these appendages adapted, splitting off into two distinct suborders with two very different evolutionary strategies.

海蝎子很快就会根据这些附肢如何适应来定义，分为两个截然不同的亚目， 具有两种截然不同的进化策略。

And as a result of this competition, sea scorpions would eventually diverge into two distinct lineages, each with its own unique strategy for dealing with the rise of the fish.

由于这种竞争，海蝎子最终会分化成两个截然不同的谱系，每个谱系都有自己独特的应对鱼类崛起的策略。

But unlike their other arthropod relatives that we share the world with today, for the sea scorpions, that move would prove to be the beginning of the end.

但与我们今天共享世界的其他节肢动物亲戚不同，对于海蝎来说， 这一举动将被证明是终结的开始。

But if you were to hang around the muddy banks of a river, you might just spot the last of the giant sea scorpions — a big weirdo called Hibbertopterus.

但如果你在河边泥泞的河岸闲逛，你可能会发现最后一只巨型海蝎——一种叫做 Hibbertopterus 的大怪人。

While sea scorpions ultimately succumbed the evolutionary pressure of powerful new vertebrates and mass extinction events, for a big window of time, they were the most fearsome and diverse arthropods around.

虽然海蝎子最终屈服于强大的新脊椎动物和大规模灭绝事件的进化压力，但在很长一段时间内， 它们是周围最可怕和最多样化的节肢动物。

And these sea scorpions had a pair of appendages that were more like paddles, which allowed them to swim, a lifestyle that put them in direct competition with jawless fish and cephalopods.

这些海蝎子有一对更像桨的附肢，可以让它们游泳， 这种生活方式使它们与无颌鱼和头足类动物直接竞争。

Scientists know " sea scorpions" by their proper, more accurate but also somewhat less cool name: eurypterids And eurypterids probably aren't ancestral to the arachnids we know as scorpions today.

科学家们通过它们正确的、更准确但也有点不那么酷的名字来了解“海蝎子”：广翅目和广翅目可能不是我们今天称为蝎子的蛛形纲动物的祖先。

Sea scorpions and true scorpions are actually sister clades that both belong to a Subphylum known as Chelicerata, an ancient group of arthropods that first appeared in the oceans of the Cambrian Period.

海蝎子和真蝎子实际上是姊妹进化枝， 都属于被称为螯肢动物亚门的亚门，这是一种最早出现在寒武纪海洋中的古老节肢动物群。

And in the seas there are the sea spiders and the primordial-looking horseshoe crabs -- living reminders of the watery origin of the chelicerates and the reign of the sea scorpions.

海洋中有海蜘蛛和长相原始的马蹄蟹——活生生地提醒着螯虾的水源起源和海蝎的统治。

This led to much greater diversity in this suborder, which is probably why 75% of all known sea scorpion species -- and more than 95% of all the specimens ever found -- belong to Eurypterina.

这导致该亚目更加多样化，这可能就是为什么 75% 的已知海蝎物种——以及超过 95% 的已发现标本——都属于广翅目。