木乃伊化石显示艾德蒙顿龙长有肉质头冠
论文地址：h
ttp://www.cell.com/current-biology/retrieve/pii/S0960982213013948
Finding the fossil
Duck-billed dinosaurs, or hadrosaurs, were large herbivores that filled the same ecological niche as deer or kangaroo today. In the past century, paleontologists have discovered several hadrosaur fossils with skin impressions pressed into the rock around the bones. These "mummy" specimens, so dubbed because they reveal more than just bone, show that hadrosaurs had pebbly skin not unlike that of today's crocodiles and birds.
鸭嘴龙是大型素食恐龙，生态地位类似现今的鹿或袋鼠。上个世纪，古生物学家发现了数具保留有皮肤印痕的鸭嘴龙化石。这些恐龙“木乃伊”的特别之处在于它们不仅保留了骨骼化石，还保存有不同于现代鸟类及鳄鱼的卵石状皮肤印痕。
But skin impressions rarely preserve well around the skull, Bell said.
“但是我们很少找到头部附近的皮肤印痕，”Bell说
Duck-billed dinosaurs, or hadrosaurs, were large herbivores that filled the same ecological niche as deer or kangaroo today. In the past century, paleontologists have discovered several hadrosaur fossils with skin impressions pressed into the rock around the bones. These "mummy" specimens, so dubbed because they reveal more than just bone, show that hadrosaurs had pebbly skin not unlike that of today's crocodiles and birds.
鸭嘴龙是大型素食恐龙，生态地位类似现今的鹿或袋鼠。上个世纪，古生物学家发现了数具保留有皮肤印痕的鸭嘴龙化石。这些恐龙“木乃伊”的特别之处在于它们不仅保留了骨骼化石，还保存有不同于现代鸟类及鳄鱼的卵石状皮肤印痕。
But skin impressions rarely preserve well around the skull, Bell said.
“但是我们很少找到头部附近的皮肤印痕，”Bell说
Bell's colleague, Federico Fanti, discovered the new E. regalis fossil in west central Alberta, about 45 miles (75 kilometers) from the town of Grande Prairie. They were surveying a well-known fossil site when Fanti noticed a string of vertebrae peeking out of a coffin-size boulder, Bell told LiveScience. The researchers had not found many bones still articulated in their original configurations, so they decided to collect the specimen.
Bell告诉我们，他的同事Federico Fanti在加拿大艾伯塔省中西部距离大草原城约75公里的地区发现了这具新的艾德蒙顿龙标本。当时他们正在勘测一片著名的化石埋藏点，Fanti注意到一串椎骨从一块棺材状的巨石中暴露出来。研究人员发现许多骨头仍然埋藏在其原本的位置，于是他们决定发掘这具标本。
"Because the block was too big to move on its own, we used a rock saw in an attempt to trim it down," Bell said. "But no sooner did we start cutting into it than we found the first skin impression. We kind of had to bite the bullet and collect the whole block."
“因为石膏包太大难以挪动，所以我们动用了岩锯打算把它分割后带走，”Bell说。“但我们一锯开围岩就发现了第一处皮肤印痕，所以大家只好咬着牙把整块石膏包运回来。”
It was seven months before the team could get to the site with a truck and trailer, because the nearby Redwillow River was so high. But in 2011, the researchers drove a truck across the river, winched the boulder onto a trailer and brought it out of the field.
由于红柳河地势较高，发掘小组寻找运输工具又花费了7个月。终于在2011年，研究员们终于找到了一辆卡车将巨石运走。
Bell告诉我们，他的同事Federico Fanti在加拿大艾伯塔省中西部距离大草原城约75公里的地区发现了这具新的艾德蒙顿龙标本。当时他们正在勘测一片著名的化石埋藏点，Fanti注意到一串椎骨从一块棺材状的巨石中暴露出来。研究人员发现许多骨头仍然埋藏在其原本的位置，于是他们决定发掘这具标本。
"Because the block was too big to move on its own, we used a rock saw in an attempt to trim it down," Bell said. "But no sooner did we start cutting into it than we found the first skin impression. We kind of had to bite the bullet and collect the whole block."
“因为石膏包太大难以挪动，所以我们动用了岩锯打算把它分割后带走，”Bell说。“但我们一锯开围岩就发现了第一处皮肤印痕，所以大家只好咬着牙把整块石膏包运回来。”
It was seven months before the team could get to the site with a truck and trailer, because the nearby Redwillow River was so high. But in 2011, the researchers drove a truck across the river, winched the boulder onto a trailer and brought it out of the field.
由于红柳河地势较高，发掘小组寻找运输工具又花费了7个月。终于在2011年，研究员们终于找到了一辆卡车将巨石运走。
While Bell was preparing the fossil, he discovered something even more amazing than skin impressions.
在Bell清理化石的时候他发现了比皮肤印痕更令人震惊的东西。
"Having a good idea of the outline of the animal, I put my chisel into the rock, not expecting to hit anything, and lo and behold, I realized I'd put my chisel straight through the middle of some skin impressions that shouldn't have been there," he said.
“我的计划是把岩石切割到近似动物轮廓的形状，然后再进行清理，于是我把凿子敲进原本应该是空无一物的多余岩石中，谁知岩石中出现了一些原本不应该有的皮肤印痕。”
Bell had found a fleshy dome extending off of the duckbill's skull — something that had never been seen before. The dome included no bones and extended from the front of the eye sockets to the back of the head. It was almost 8 inches (20 centimeters) tall at its highest point and about 13 inches (33 cm) long.
Bell找到的是一个从恐龙头骨上方衍生出的肉质半圆形冠状突起——类似的结构以前从未在这种恐龙身上发现过。冠状突起的内部没有骨骼，从眼睛后方一直延伸到脑后。头冠最高点大约有8英尺（约20厘米），长度约为13英寸（约33厘米）。
在Bell清理化石的时候他发现了比皮肤印痕更令人震惊的东西。
"Having a good idea of the outline of the animal, I put my chisel into the rock, not expecting to hit anything, and lo and behold, I realized I'd put my chisel straight through the middle of some skin impressions that shouldn't have been there," he said.
“我的计划是把岩石切割到近似动物轮廓的形状，然后再进行清理，于是我把凿子敲进原本应该是空无一物的多余岩石中，谁知岩石中出现了一些原本不应该有的皮肤印痕。”
Bell had found a fleshy dome extending off of the duckbill's skull — something that had never been seen before. The dome included no bones and extended from the front of the eye sockets to the back of the head. It was almost 8 inches (20 centimeters) tall at its highest point and about 13 inches (33 cm) long.
Bell找到的是一个从恐龙头骨上方衍生出的肉质半圆形冠状突起——类似的结构以前从未在这种恐龙身上发现过。冠状突起的内部没有骨骼，从眼睛后方一直延伸到脑后。头冠最高点大约有8英尺（约20厘米），长度约为13英寸（约33厘米）。
"You can actually see the wrinkles in the skin that indicate that it had some flexibility to it," Bell said.
“你可以看到皮肤表面的褶皱，这说明冠状物在动物活着的时候是非常有弹性的，”Bell介绍说。
In modern birds, such combs are typically used for sexual display. They're found in both sexes in birds, so the presence of the comb tells researchers nothing about their dinosaur specimen's sex. The bones they do have belong to the neck and head, and don't reveal sex either.
在现代鸟类之中类似的构造大多属于性别特征，通常用于炫耀。但也有些鸟类雌雄个体都具有头冠，所以这个冠状物的发现对于研究员们确定恐龙的性别并没有帮助。当然他们也无法从恐龙保留下来的颈部骨骼和头骨中得知相关的信息。
"What we need to find now are additional specimens that show this structure, and perhaps by comparing their sizes or relative development, we might get an idea of their sex," Bell said.
“我们需要更多的保留有类似结构的标本，也许通过比较它们的尺寸和亲缘关系，或许我们能在恐龙性别的研究中有所发现。”Bell说。
“你可以看到皮肤表面的褶皱，这说明冠状物在动物活着的时候是非常有弹性的，”Bell介绍说。
In modern birds, such combs are typically used for sexual display. They're found in both sexes in birds, so the presence of the comb tells researchers nothing about their dinosaur specimen's sex. The bones they do have belong to the neck and head, and don't reveal sex either.
在现代鸟类之中类似的构造大多属于性别特征，通常用于炫耀。但也有些鸟类雌雄个体都具有头冠，所以这个冠状物的发现对于研究员们确定恐龙的性别并没有帮助。当然他们也无法从恐龙保留下来的颈部骨骼和头骨中得知相关的信息。
"What we need to find now are additional specimens that show this structure, and perhaps by comparing their sizes or relative development, we might get an idea of their sex," Bell said.
“我们需要更多的保留有类似结构的标本，也许通过比较它们的尺寸和亲缘关系，或许我们能在恐龙性别的研究中有所发现。”Bell说。
It's not clear whether the comb is a feature only of E. regalis or if other duckbills might have had similar fleshy accessories. Skin associated with the head may not preserve well, meaning that other combs have vanished without a trace, Bell said. Or, they may have been overlooked. In the past, paleontologists considered skin impressions less interesting than bones, so they ignored them.
"People would actually remove and destroy the skin that's been preserved in order to get to the bones," Bell said.
目前尚不清楚肉质头冠是否仅存在于艾德蒙顿龙身上还是广泛存在于其他鸭嘴龙之中。“头骨和皮肤通常很难保存下来，也许其他恐龙的头冠在形成化石的过程中已经完全消失，”Bell说。“或者仅仅是被我们忽视了：从前的古生物学家对骨骼化石的兴趣远大于皮肤印痕，所以类似的痕迹常常被遗忘，为了得到恐龙的骨骼，一些皮肤痕迹往往就在发掘的过程中被破坏了。”
Modern preparation has the potential to lead to a deeper understanding of dinosaurs, he said. "There's going to be no end of new and very surprising discoveries to come," Bell said.
The researchers report their findings today (Dec. 12) in the journalCurrent Biology.
”现代化的科学研究手段会使得我们对恐龙有更进一步的了解，无疑我们还会有更加令人兴奋的发现。”
研究结果目前已经发表在12月的Current Biology杂志上。
Follow Stephanie Pappas on Twitter and Google+. Follow us@livescience, Facebook & Google+. Original article on LiveScience.
"People would actually remove and destroy the skin that's been preserved in order to get to the bones," Bell said.
目前尚不清楚肉质头冠是否仅存在于艾德蒙顿龙身上还是广泛存在于其他鸭嘴龙之中。“头骨和皮肤通常很难保存下来，也许其他恐龙的头冠在形成化石的过程中已经完全消失，”Bell说。“或者仅仅是被我们忽视了：从前的古生物学家对骨骼化石的兴趣远大于皮肤印痕，所以类似的痕迹常常被遗忘，为了得到恐龙的骨骼，一些皮肤痕迹往往就在发掘的过程中被破坏了。”
Modern preparation has the potential to lead to a deeper understanding of dinosaurs, he said. "There's going to be no end of new and very surprising discoveries to come," Bell said.
The researchers report their findings today (Dec. 12) in the journalCurrent Biology.
”现代化的科学研究手段会使得我们对恐龙有更进一步的了解，无疑我们还会有更加令人兴奋的发现。”
研究结果目前已经发表在12月的Current Biology杂志上。
Follow Stephanie Pappas on Twitter and Google+. Follow us@livescience, Facebook & Google+. Original article on LiveScience.