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先有羽毛,后有鸟!

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2019年06月05日

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Feathers came first, then birds

先有羽毛,后有鸟!
先有羽毛,后有鸟!

New research, led by the University of Bristol, suggests that feathers arose 100 million years before birds -- changing how we look at dinosaurs, birds, and pterosaurs, the flying reptiles.

由布里斯托尔大学领导的一项最新研究表明,羽毛的出现比鸟类早1亿年,这改变了我们对恐龙、鸟类和翼龙(一种会飞的爬行动物)的看法。

It also changes our understanding of feathers themselves, their functions and their role in some of the largest events in evolution.

它还改变了我们对羽毛本身、它们的功能以及它们在进化过程中某些重大事件中的作用的理解。

The new work, published in the journal Trends in Ecology & Evolution combines new information from palaeontology and molecular developmental biology.

这项发表在《生态与进化趋势》杂志上的新研究结合了古生物学和分子发育生物学的新信息。

先有羽毛,后有鸟!

The key discovery came earlier in 2019, when feathers were reported in pterosaurs -- if the pterosaurs really carried feathers, then it means these structures arose deep in the evolutionary tree, much deeper than at the point when birds originated.

关键的发现出现在2019年早些时候,当时有报道称翼龙身上长有羽毛——如果翼龙身上真的长有羽毛,那么这意味着这些结构出现在进化树的深处,比鸟类起源时要深得多。

Lead author, Professor Mike Benton, from the University of Bristol's School of Earth Sciences, said: "The oldest bird is still Archaeopteryx first found in the Late Jurassic of southern Germany in 1861, although some species from China are a little older.

研究报告的主要撰写者、布里斯托尔大学地球科学学院的迈克·本顿教授说:“目前发现的最古老的鸟类仍然是始祖鸟,1861年始祖鸟首次出现在德国南部的侏罗纪晚期,尽管一些来自中国的始祖鸟的年龄稍大一些。”

"Those fossils all show a diversity of feathers -- down feathers over the body and long, vaned feathers on the wings. But, since 1994, palaeontologists have been contending with the perturbing discovery, based on hundreds of amazing specimens from China, that many dinosaurs also had feathers."

“这些化石都显示出羽毛的多样性——身体上的羽绒羽毛和翅膀上长长的带叶片的羽毛。但是,自从1994年以来,古生物学家们就一直在与一个令人不安的发现作斗争,这个发现是基于数百个来自中国的令人惊奇的标本,许多恐龙也有羽毛。”

Co-author, Baoyu Jiang from the University of Nanjing, added: "At first, the dinosaurs with feathers were close to the origin of birds in the evolutionary tree.

研究报告的撰写者之一、南京大学的蒋宝玉补充说:“起初,在进化树上,长羽毛的恐龙与鸟类的起源非常接近。

"This was not so hard to believe. So, the origin of feathers was pushed back at least to the origin of those bird-like dinosaurs, maybe 200 million years ago."

“这并不难相信。所以,羽毛的起源至少可以追溯到那些类鸟恐龙的起源,可能是2亿年前。”

Dr Maria McNamara, co-author from University College Cork, said: "Then, we had the good fortune to work on a new dinosaur from Russia, Kulindadromeus.

科克大学学院的合著者玛丽亚·麦克纳马拉博士说:“然后,我们有幸研究了一种来自俄罗斯的新恐龙——库林达洛梅厄斯。

"This dinosaur showed amazingly well-preserved skin covered with scales on the legs and tail, and strange whiskery feathers all over its body.

这只恐龙的腿和尾巴上覆盖着鳞片,皮肤保存得非常完好,全身长满了奇怪的胡须羽毛。

"What surprised people was that this was a dinosaur that was as far from birds in the evolutionary tree as could be imagined. Perhaps feathers were present in the very first dinosaurs."

“让人们感到惊讶的是,这是一种恐龙,它与进化树上的鸟类之间的距离是人们所能想象的最远的。也许羽毛存在于最早的恐龙身上。”

Danielle Dhouailly from the University of Grenoble, also a co-author, works on the development of feathers in baby birds, especially their genomic control. She said: "Modern birds like chickens often have scales on their legs or necks, and we showed these were reversals: what had once been feathers had reversed to be scales.

格勒诺布尔大学(University of Grenoble)的丹妮尔·杜维利(Danielle Dhouailly)也是该研究的合著者之一,她的研究方向是幼鸟羽毛的发育,尤其是它们的基因组控制。她说:“像鸡这样的现代鸟类的腿上或脖子上经常有鳞片,我们发现这些是颠倒过来的:曾经是羽毛的东西现在变成了鳞片。”

"In fact, we have shown that the same genome regulatory network drives the development of reptile scales, bird feathers, and mammal hairs. Feathers could have evolved very early."

“事实上,我们已经证明,同样的基因组调控网络驱动爬行动物鳞片、鸟类羽毛和哺乳动物毛发的发育。羽毛可能很早就进化出来了。”

先有羽毛,后有鸟!

Baoyu Jiang continued: "The breakthrough came when we were studying two new pterosaurs from China.

蒋宝玉继续说道:“当我们研究来自中国的两只新的翼龙时,我们取得了突破。”

"We saw that many of their whiskers were branched. We expected single strands -- monofilaments -- but what we saw were tufts and down feathers. Pterosaurs had feathers."

“我们看到它们的许多胡须都是分叉的。我们期待单股、单丝,但我们看到的是簇绒和羽毛。翼龙有羽毛。”

Professor Benton added: "This drives the origin of feathers back to 250 million years ago at least.

本顿教授补充说:“这使得羽毛的起源至少可以追溯到2.5亿年前。”

"The point of origin of pterosaurs, dinosaurs and their relatives. The Early Triassic world then was recovering from the most devastating mass extinction ever, and life on land had come back from near-total wipe-out.

“翼龙、恐龙及其近亲的起源点。当时的三叠纪早期世界正从有史以来最具毁灭性的物种大灭绝中恢复过来,陆地上的生命也从几近灭绝的状态中恢复过来。

"Palaeontologists had already noted that the new reptiles walked upright instead of sprawling, that their bone structure suggested fast growth and maybe even warm-bloodedness, and the mammal ancestors probably had hair by then.

古生物学家已经注意到,这种新的爬行动物直立行走,而不是四肢伸开,它们的骨骼结构表明它们生长迅速,甚至可能是温血,而哺乳动物的祖先可能在那时就有了毛发。

"So, the dinosaurs, pterosaurs and their ancestors had feathers too. Feathers then probably arose to aid this speeding up of physiology and ecology, purely for insulation. The other functions of feathers, for display and of course for flight, came much later."

所以,恐龙、翼龙和它们的祖先也有羽毛。羽毛的出现可能是为了促进生理和生态的加速,纯粹是为了保温。羽毛的其他功能,用于展示,当然也用于飞行,要晚得多。”


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