琥珀化石更新螃蟹进化

Fossils trapped in amber have been among paleontology's most fascinating finds in recent years -- globs of hardened ancient tree resin have captured tantalizing details about spiders, lizards, microscopic animals, insects, birds and even a tiny dinosaur that are often missing from fossils found in rock.

琥珀中的化石是古生物学近年来最吸引人的发现之一--古树树脂硬化的球状化石捕捉到了蜘蛛、蜥蜴、微小动物、昆虫、鸟类甚至是岩石化石中经常缺失的一种微小恐龙的诱人的细节。

However, all these creatures were land lubbers that you might expect to encounter on a tree trunk or branch.

然而，所有这些生物都是陆地上的圈套，你可能会在树干或树枝上遇到它们。

Now, scientists have found the oldest aquatic animal preserved in amber -- and it's the most complete crab fossil ever discovered.

现在，科学家们在琥珀中发现了最古老的水生动物--这是迄今为止发现的最完整的螃蟹化石。

"The specimen is spectacular, it is one of a kind. It's absolutely complete and is not missing a single hair on the body, which is remarkable," said Javier Luque, a postdoctoral researcher in the Department of Organismic and Evolutionary Biology at Harvard University, in a news release.

哈佛大学组织与进化生物学系博士后贾维尔·卢克在一份新闻稿中说：“这个标本很壮观，它是一种独一无二的标本。它绝对是完整的，身上一根毛发也没有掉下来，这是非常了不起的。”

He was the lead author of the study that published Thursday in the journal Science Advances.

他是周四发表在《科学进步》杂志上的这项研究的主要作者。

The Chinese, US and Canadian scientists working on the amber specimen, which originated from northern Myanmar, named the tiny crab Cretapsara athanata.

来自缅甸北部的中国、美国和加拿大科学家正在研究琥珀标本，命名为小螃蟹Cretapsara athanata。

The name references the Cretaceous, the dinosaur-era period during which this crab lived, and Apsara, a spirit of the clouds and waters in South and Southeast Asian mythology.

这个名字指的是白垩纪，这只螃蟹生活的恐龙时代，以及南亚和东南亚神话中的一种云和水的精灵阿普萨拉。

The species name is based on "athanatos," which means immortal in Greek, referring to its lifelike preservation in amber.

这个物种的名字是以“athanatos”为基础的，意思是在希腊语中是不朽的，意指它在琥珀中栩栩如生的保存。

In looks, the 100-million-year-old creature superficially resembles crabs that scuttle around shores today.

从外表上看，这只有1亿年历史的生物表面上就像螃蟹，今天在海岸附近到处都有分布。

Computerized tomography scans revealed delicate body parts like antennae, gills and fine hairs on the mouth parts.

电脑断层扫描显示出敏感的身体部位，如触角、鳃和口腔部位的细毛。

The creature was only 5 millimeters long and likely a baby crab.

这个生物只有5毫米长，很可能是一只小螃蟹。

The researchers think that Cretapsara was neither a marine crab nor completely land dwelling.

研究人员认为，Cretapsara既不是海生螃蟹，也不是陆栖蟹。

They think it would have lived in fresh water, or perhaps brackish water, on the forest floor.

他们认为它会生活在森林地板上的淡水中，或者可能是咸水中。

It was also possible, they said, that it was migrating onto land like the famous red Christmas Island crabs that release their babies into the ocean and later swarm back onto land.

他们还说，它也有可能迁移到陆地上，就像著名的红圣诞岛螃蟹，它们把它们的宝宝放进海洋，然后又蜂拥回到陆地上。

While the oldest crab fossils date back to the Jurassicperiod more than 200 million years ago, fossils of non-marine crabs are sparse and largely incomplete.

最古老的螃蟹化石可以追溯到两亿多年前的侏罗纪，而非海生螃蟹的化石则很稀少，而且大部分都不完整。

The researchers said that Cretapsara proves that crabs made the leap from the sea to land and fresh water during the dinosaur era, not during the mammal era, as previously thought, pushing the evolution of non-marine crabs much farther back in time.

研究人员说，克拉塔萨拉证明，螃蟹在恐龙时代就出现了，而不是哺乳动物时代，从海洋迁徙到了陆地和淡水，这推动了非海洋螃蟹的进化研究。