古代致命的鳄鱼模仿鲸鱼统治海洋

古代致命的鳄鱼模仿鲸鱼统治海洋

Some 170 million years ago, deadly Jurassic crocodiles ruled the oceans. But researchers think they have unlocked the key to their successful reign of terror -- by mimicking the shape and senses of whales and dolphins.

大约1.7亿年前，致命的侏罗纪鳄鱼统治着海洋。但研究人员认为，他们通过模仿鲸鱼和海豚的形状和感觉，找到了成功统治恐怖的关键。

The extinct beasts -- known as thalattosuchians -- could reach up to 10 meters in size andevolved from their land-living ancestors by adapting their limbs into flippers, developing fluked tails for swimming and streamlining their bodies, making them formidable, fast-swimming predators.

这种已经灭绝的动物被称为海樽目动物，它们的体型可以达到10米，它们通过将四肢变成鳍状肢，进化出有蹼的尾巴来游泳，使身体流线型，使它们成为强大的、快速游动的食肉动物，从陆地上的祖先进化而来。

The teleosauroid Machimosaurus rex, the largest semi-aquatic thalattosuchian, could reach up to 10 meters in size, and is thought to have fed on hard prey like turtles due to its teeth, paleontologist Julia Schwab told CNN.

古生物学家朱莉娅·施瓦布在接受CNN采访时表示，霸王龙是最大的半水生海洋生物，身长可达10米，据信它以海龟等硬物为食，因为它们有牙齿。

Plesiosuchus, the largest marine thalattosuchian that lived in the open ocean, measured about 6.8 meters and hunted anything from squid-like creatures to fish and other marine reptiles.

蛇颈龙是生活在开阔海域的最大的海洋生物，长约6.8米，捕食从鱿鱼类动物到鱼类和其他海洋爬行动物等各种动物。

By studying the crocodile's skulls, researchers also found that they had adapted part of the inner ear as they adjusted to life in the oceans.

通过研究鳄鱼的头骨，研究人员还发现，当他们适应海洋生活时，他们已经适应了内耳的一部分。

Paleontologists from the University of Edinburgh analyzed computerized axial tomography (CAT) scans of more than a dozen fossil skulls to study the vestibular system -- the three looping semicircular canals of the inner ear which control balance.

来自爱丁堡大学的古生物学家分析了十多个头骨化石的计算机轴位断层扫描(CAT)来研究前庭系统——内耳控制平衡的三个环状半规管。

Researchers found that as the creatures entered their semi-aquatic phase, the canals started to become fatter, like those of whales and dolphins.

研究人员发现，当这些生物进入半水生阶段时，规管开始变得更胖，就像鲸鱼和海豚一样。

This shape, experts say, made the creature's sensory system less sensitive, and better suited to life in the oceans.

专家说，这种形状使这种生物的感觉系统不那么灵敏，更适合海洋生物。

"Sensory organs such as the inner ear are key to understand how ancient animals lived. We found that marine crocodile relatives have a very unique inner ear shape, similar to other water-living reptiles and today's whales," Julia Schwab, a PhD student in the University of Edinburgh's School of GeoSciences who led the study, said in a statement.

像内耳这样的感觉器官是了解古代动物生活方式的关键。研究负责人、爱丁堡大学地球科学学院的茱莉亚·施瓦布博士在一份声明中说:“我们发现，海洋鳄鱼的近亲有着非常独特的内耳形状，与其他水生爬行动物和今天的鲸鱼很相似。”

On land, animals need a sensitive sense of balance to cope with gravity and complex landscapes, but in the ocean, buoyancy keeps animals afloat.

在陆地上，动物需要一种灵敏的平衡感来应对重力和复杂的地形，但在海洋里，浮力使动物浮在水面上。

The adaptation came in response to the crocodile's new deep water environment, rather than driving them into it, scientists say.

科学家说，这种适应是对鳄鱼新的深水环境的反应，而不是驱使它们进入深水环境。

"The ancient aquatic crocs developed unusual inner ears after modifying their skeletons to become better swimmers. Whales also changed their ears in a similar way, but did it soon after entering the water," Dr Steve Brusatte, senior author on the study, said.

古代的水生鳄鱼通过改变骨骼使自己成为更好的游泳者，从而发展出了不寻常的内耳。鲸鱼也以类似的方式改变了它们的耳朵，但在进入水中后不久就改变了。” 该研究的资深作者史蒂夫·布鲁萨特博士说。

In a paper, published in the journal Proceedings of the National Academy of Sciences, experts noted that a similar change occurred independently in whales, leading experts to believe that each species mimicked each other's changes.

在一篇发表在《美国国家科学院院刊》杂志上的论文中，专家们指出，类似的变化是在鲸鱼身上独立发生的，这让专家们相信，每个物种都在模仿彼此的变化。

"It seems like the crocs and whales took similar, but different, evolutionary routes from land to water," Brusatte added.

“从陆地到海洋的进化，鳄鱼和鲸鱼似乎走了相似但不同的进化路线，”布鲁萨特补充道。