经济学人下载:食草系鳄鱼(1)

Compared with mammals, living members of the crocodile clan have exceptionally boring dentition.
和哺乳动物相比，现存鳄鱼家族的成员有着异常无趣的牙列。

From the slender-snouted gharials of India and the nocturnal caimans of South America
从印度的非洲狭吻鳄和南美的夜行凯门鳄

to the saltwater behemoths of the South Pacific, crocodile teeth vary little in morphology.
到南太平洋的盐水巨兽，鳄鱼的牙齿形态变化不大。

All are conical and pointed. Each tooth in an animal's mouth is almost identical to its neighbours—
它们所有类型的牙齿都是圆圆尖尖的。动物嘴里的每颗牙齿几乎都和它的邻居一样—

as befits a group of that feed on a mixture of fish and the occasional careless beast
这群动物以各种鱼以及因粗心而偶尔

that strays too close to the shore, or even into the water itself.
离海岸太近或者甚至游到水里去的野兽为食。

This predilection for pointed fangs is not, however, how it has always been.
但对尖牙的这种偏爱并非一直如此。

During the days of the dinosaurs, the Jurassic and Cretaceous periods,
在恐龙时代，侏罗纪和白垩纪，

crocodile-clan members showed extraordinary dental diversity.
鳄鱼家族成员的牙齿展现出了非凡的多样性。

Many of their teeth have proved so bizarre that some palaeontologists have theorised that,
它们的许多牙齿被证明是非常怪异的，以至于一些古生物学家推断

far from being carnivorous, these ancient species might have been eating plants.
这些远古物种根本不是食肉动物，它们可能以植物为食。

A study published this week in Current Biology, by Keegan Melstrom and Randall Irmis at the University of Utah, confirms this.
本周犹他大学的Keegan Melstrom和Randall Irmis在《Current Biology》发表的一项研究证实了这一点。

It also suggests that herbivory evolved in the crocodile clan on several occasions.
该研究还表明鳄鱼家族的食草性进化了好几次。

When trying to work out what ancient animals ate, palaeontologists usually look to modern analogues.
当古生物学家试图弄清楚古代动物吃什么时，他们通常会参照现代的类似物。

If teeth from an extinct beast match those of a modern species, the two are quite likely to have had similar diets.
如果灭绝动物的牙齿与现代动物的牙齿相匹配，那么这两种动物很可能有着相似的饮食习惯。

With extinct crocodilians, however, this palaeontological tactic has routinely been stymied
但对于已经灭绝的鳄鱼来说，这种古生物学策略经常受到阻碍

because their teeth, which are adorned with many rows of cusps and wrinkled enamel,
因为它们的牙齿上布满了一排排的牙尖和皱巴巴的牙釉质

look nothing like what is found in the mouths of animals alive today.
看起来一点也不像在今天活着的动物嘴里发现的东西。

This has left the topic of what ancient crocodilians ate very much up for grabs.
这就留下了古代鳄鱼吃什么的话题。

Some palaeontologists argue that certain species, such as Simosuchus clarki were vegetarian.
一些古生物学家认为某些种类，如迷你鳄鱼是素食动物。

To solve the puzzle Mr Melstrom and Dr Irmis turned to Orientation Patch Count Rotated (OPCR) analysis.
为了解决这个难题，Melstrom和Irmis博士转向了旋转定位补丁计数（OPCR）分析。