古代致命的鱷魚模仿鯨魚統(tǒng)治海洋

古代致命的鱷魚模仿鯨魚統(tǒng)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.

大約1.7億年前，致命的侏羅紀(jì)鱷魚統(tǒng)治著海洋。但研究人員認(rèn)為，他們通過模仿鯨魚和海豚的形狀和感覺，找到了成功統(tǒng)治恐怖的關(guān)鍵。

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.

這種已經(jīng)滅絕的動物被稱為海樽目動物，它們的體型可以達到10米，它們通過將四肢變成鰭狀肢，進化出有蹼的尾巴來游泳，使身體流線型，使它們成為強大的、快速游動的食肉動物，從陸地上的祖先進化而來。

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.

古生物學(xué)家朱莉婭·施瓦布在接受CNN采訪時表示，霸王龍是最大的半水生海洋生物，身長可達10米，據(jù)信它以海龜?shù)扔参餅槭常驗樗鼈冇醒例X。

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.

蛇頸龍是生活在開闊海域的最大的海洋生物，長約6.8米，捕食從魷魚類動物到魚類和其他海洋爬行動物等各種動物。

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.

通過研究鱷魚的頭骨，研究人員還發(fā)現(xiàn)，當(dāng)他們適應(yīng)海洋生活時，他們已經(jīng)適應(yīng)了內(nèi)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.

來自愛丁堡大學(xué)的古生物學(xué)家分析了十多個頭骨化石的計算機軸位斷層掃描(CAT)來研究前庭系統(tǒng)——內(nèi)耳控制平衡的三個環(huán)狀半規(guī)管。

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

研究人員發(fā)現(xiàn)，當(dāng)這些生物進入半水生階段時，規(guī)管開始變得更胖，就像鯨魚和海豚一樣。

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

專家說，這種形狀使這種生物的感覺系統(tǒng)不那么靈敏，更適合海洋生物。

"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.

像內(nèi)耳這樣的感覺器官是了解古代動物生活方式的關(guān)鍵。研究負(fù)責(zé)人、愛丁堡大學(xué)地球科學(xué)學(xué)院的茱莉亞·施瓦布博士在一份聲明中說:“我們發(fā)現(xiàn)，海洋鱷魚的近親有著非常獨特的內(nèi)耳形狀，與其他水生爬行動物和今天的鯨魚很相似。”

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

在陸地上，動物需要一種靈敏的平衡感來應(yīng)對重力和復(fù)雜的地形，但在海洋里，浮力使動物浮在水面上。

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

科學(xué)家說，這種適應(yīng)是對鱷魚新的深水環(huán)境的反應(yīng)，而不是驅(qū)使它們進入深水環(huán)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.

古代的水生鱷魚通過改變骨骼使自己成為更好的游泳者，從而發(fā)展出了不尋常的內(nèi)耳。鯨魚也以類似的方式改變了它們的耳朵，但在進入水中后不久就改變了。” 該研究的資深作者史蒂夫·布魯薩特博士說。

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.

在一篇發(fā)表在《美國國家科學(xué)院院刊》雜志上的論文中，專家們指出，類似的變化是在鯨魚身上獨立發(fā)生的，這讓專家們相信，每個物種都在模仿彼此的變化。

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

“從陸地到海洋的進化，鱷魚和鯨魚似乎走了相似但不同的進化路線，”布魯薩特補充道。