藉助衛星而發現地核中的噴流

原始網址：www.sciencedaily.com/releases/2016/12/161219134450.htm

藉助衛星而發現地核中的噴流

科學家藉助衛星產生的最新資料，而做出了地球的「X光」影像。從中他們發現有道噴流存在於地球的液態鐵核心內部。

領導這項研究的里茲大學Phil Livermore博士表示：「歐洲太空總署的Swarm衛星正提供給我們有史以來最清楚的地核X光影像。從中我們不但能首度清楚看見這道噴流(jet stream)的存在，同時也可以藉此了解為何它會於此形成。」

「我們可以清楚看出這是一道環繞北極的液態鐵加速帶，如同大氣中的噴射氣流一般。」里茲大學地球與環境學院的Livermore博士說。

由於地核所處的位置遠在3,000公里厚的岩石下方，因此多年以來科學家是透過測量地球磁場的性質來研究地核―這是少數可用選項之一。

過往的研究中已經發現，磁場變化意味著外核的鐵在北半球的流動速度比較快，尤其是阿拉斯加和西伯利亞下方。

但是由Swarm衛星提供的新數據顯示，這些變化實際上是由一道噴流導致，其流動速度高達每年40公里。

這是一般外核流速的三倍，更是地球板塊移動速度的數百倍至數千倍以上。

歐洲太空總署的Swarm任務，主要是利用三顆衛星同步測量並分離產生自地球不同區域的磁場訊號，這些來源包括了地核、地函、地殼、海洋、電離層和磁層。這些衛星對地核產生的磁場提供了迄今最清楚的資訊。

刊登於《自然―地質科學》的研究發現此噴流的方向，跟地核內部兩塊不同區域之間邊界的方向一致。他們認為這道噴流可能是因為地核內部的流體，從兩個方向往這道邊界匯聚，接著往側邊擠出而形成。

共同作者，里茲大學數學院的Rainer Hollerbach表示：「當然，你需要一股力量才能將流體推往這道邊界。它可能由浮力提供，或許更有可能是來自於地核內部磁場的變化。」

歐洲太空總署Swarm任務的主持人，Rune Floberghagen表示：「[這項計畫]還可能帶來更驚人的發現。磁場無時無刻都在變動著，甚至會改變這道噴流的方向。」

「這道特徵是因為Swarm才得以對地球深部首度作出的發現之一。有了現今可以達到的前所未見高解析度，這是相當令人振奮的時刻—我們只是還不知道對地球的下一步發現會是什麼。」

共同作者，丹麥科技大學的Chris Finlay博士表示：「關於地核我們所知的還遠遠不及太陽。在更加理解我們地球內部的運作方式上，這道噴流的發現無疑是激勵人心的一步。」

 

Satellites help discover a jet stream in the Earth's core

A jet stream within the Earth's molten iron core has been discovered by scientists using the latest satellite data that helps create an 'x-ray' view of the planet.

Lead researcher Dr Phil Livermore, from the University of Leeds, said: "The European Space Agency's Swarm satellites are providing our sharpest x-ray image yet of the core. We've not only seen this jet stream clearly for the first time, but we understand why it's there."

"We can explain it as an accelerating band of molten iron circling the North Pole, like the jet stream in the atmosphere," said Dr Livermore, from the School of Earth and Environment at Leeds.

Because of the core's remote location under 3,000 kilometres of rock, for many years scientists have studied the Earth's core by measuring the planet's magnetic field -- one of the few options available.

Previous research had found that changes in the magnetic field indicated that iron in the outer core was moving faster in the northern hemisphere, mostly under Alaska and Siberia.

But new data from the Swarm satellites has revealed these changes are actually caused by a jet stream moving at more than 40 kilometres per year.

This is three times faster than typical outer core speeds and hundreds of thousands of times faster than the speed at which the Earth's tectonic plates move.

The European Space Agency's Swarm mission features a trio of satellites which simultaneously measure and untangle the different magnetic signals which stem from Earth's core, mantle, crust, oceans, ionosphere and magnetosphere. They have provided the clearest information yet about the magnetic field created in the core.

The study, published today in Nature Geoscience, found the position of the jet stream aligns with a boundary between two different regions in the core. The jet is likely to be caused by liquid in the core moving towards this boundary from both sides, which is squeezed out sideways.

Co-author Professor Rainer Hollerbach, from the School of Mathematics at Leeds, said: "Of course, you need a force to move the liquid towards the boundary. This could be provided by buoyancy, or perhaps more likely from changes in the magnetic field within the core."

Rune Floberghagen, ESA's Swarm mission manager, said: "Further surprises are likely. The magnetic field is forever changing, and this could even make the jet stream switch direction.

"This feature is one of the first deep-Earth discoveries made possible by Swarm. With the unprecedented resolution now possible, it's a very exciting time -- we simply don't know what we'll discover next about our planet."

Co-author Dr Chris Finlay, from the Technical University of Denmark said: "We know more about the Sun than the Earth's core. The discovery of this jet is an exciting step in learning more about our planet's inner workings."

原始論文：Philip W. Livermore, Rainer Hollerbach, Christopher C. Finlay.An accelerating high-latitude jet in Earth’s core. Nature Geoscience, 2016; DOI: 10.1038/ngeo2859

引用自：University of Leeds. "Satellites help discover a jet stream in the Earth's core." ScienceDaily. ScienceDaily, 19 December 2016.

數千年前急劇發生的氣候變遷成因為何？新研究推翻了之前的假說

原文網址：www.sciencedaily.com/releases/2016/12/161219115304.htm

數千年前急劇發生的氣候變遷成因為何？新研究推翻了之前的假說

約莫12,900年前發生了一起急劇的氣候變遷事件，也促成了新仙女木期開始。以往認為這起事件的肇因為一或多顆彗星/火流星撞擊北美大陸，但發表於《第四紀科學期刊》的兩篇新研究卻否決了這門假說。

在新仙女木期(Younger Dryas)之前，氣候正從冰河期狀態逐漸暖化成跟今日相仿的溫度，之前覆蓋北美的廣大冰層也已經完全消融。然而，在大約12,900年前，氣溫卻突然驟降回冰河期的狀態，並持續了將近1200年。於此同時，北美洲的猛瑪象和乳齒象也邁入滅絕。

這兩篇論文挑戰了撞擊理論中，其他科學家曾發表並用來支持該理論的兩條線索。第一條線索是新仙女木期最初堆積的沉積物中，奈米尺寸的鑽石含量有增加現象。另一條線索則是從一處重要考古場址的古火焰(paleofire)證據中，得出新仙女木期開始時曾發生相當嚴重的野火事件。支持者主張第一條線索中的鑽石為撞擊事件的產物，第二條線索則代表此事件引發了遍及整個北美大陸的野火。

兩篇新論文皆指出用來支持這兩條線索的證據和解釋並站不住腳。「撞擊說的擁護者發表說他們找到了六方白碳石(lonsdaleite)，這種罕見的鑽石型態通常跟衝擊作用有關。然而，我們卻證實他們把石墨烯和石墨烷的多晶聚集體(polycrystalline aggregate)誤認成了六方白碳石。」其中一篇論文的第一作者Tyrone Daulton博士說。「此外，我們也證明了撞擊說擁護者發表的奈米鑽石含量測量結果具有重大缺陷。在新仙女木期開始時，並沒有證據可以指出奈米鑽石的含量有出現高峰，因此無法推論當時曾經發生過撞擊事件。」

第二篇論文的第一作者Andrew Scott教授表示：「新仙女木期是因撞擊事件而導致的想法，確實相當有趣也非常引人注目。但是過去數年以來，越來越多的方法論研究成果，卻無法支持這則故事。我們的研究顯示過往被認為代表了這起事件的記號，實際上有很多是辨識錯誤或判讀錯誤之下的結果。」

Studies refute hypothesis on what caused abrupt climate change thousands of years ago

Two new studies in the Journal of Quaternary Science refute the hypothesis that one or more comets/bolides struck North America approximately 12,900 years ago triggering rapid climate change and the start of the Younger Dryas period.

Prior to the Younger Dryas, the climate had gradually warmed from glacial conditions to near modern temperatures, and the massive ice sheets in North America were in full retreat; however, approximately 12,900 years ago, temperatures rapidly plummeted and returned to glacial conditions for about a 1200 year long period. Also about this time, the mammoths and mastodons became extinct in North America.

The two papers challenge two lines of evidence reported and used by others to support the impact theory. One is the report of elevated concentrations of nanometer-sized diamonds in sediments deposited at the onset of the Younger Dryas. It is claimed that these diamonds were formed during an impact. The other is the interpretation that paleofire evidence at a key archaeological site demonstrates massive wildfires at the beginning of the Younger Dryas. It is claimed that the impact caused wildfires that spanned the continent.

Each paper shows that the evidence and interpretations supporting these two lines of arguments do not stack up. "Impact proponents report the rare form of diamond, lonsdaleite, that is usually associated with shock processing; however, we show that they misidentified polycrystalline aggregates of graphene and graphane as lonsdaleite," said Dr. Tyrone Daulton, lead author of one of the papers. "Further, we show that the nanodiamond concentration measurements reported by impact proponents are critically flawed. There is no evidence for a spike in the nanodiamond concentration at the onset of the Younger Dryas to suggest that an impact event occurred."

Prof. Andrew Scott, lead author of the second paper said, "The idea of a Younger Dryas impact was an interesting one that has drawn much attention; however, increasingly methodological research over the past few years has failed to corroborate that story. Our research has shown that many of the markers for such an event have been misinterpreted or misidentified."

原始論文：1. Tyrone L. Daulton, Sachiko Amari, Andrew C. Scott, Mark Hardiman, Nicholas Pinter, R. Scott Anderson. Comprehensive analysis of nanodiamond evidence relating to the Younger Dryas Impact Hypothesis. Journal of Quaternary Science, 2016; DOI: 10.1002/jqs.2892

2. Andrew C. Scott, Mark Hardiman, Nicholas Pinter, R. Scott Anderson, Tyrone L. Daulton, Ana Ejarque, Paul Finch, Alice Carter-champion. Interpreting palaeofire evidence from fluvial sediments: a case study from Santa Rosa Island, California, with implications for the Younger Dryas Impact Hypothesis. Journal of Quaternary Science, 2016; DOI: 10.1002/jqs.2914

引用自：Wiley. "Studies refute hypothesis on what caused abrupt climate change thousands of years ago." ScienceDaily. ScienceDaily, 19 December 2016.

原文網址：www.sciencedaily.com/releases/2016/12/161215085909.htm

改寫板塊厚度的定義？研究橄欖石對如何測量地球表面提供了新資訊

板塊構造學說意指地球表面是由好幾塊會彼此遠離與靠近的板塊組成。自1960年代開始，科學家便利用這項學說來解釋火山和地震為何會在某些地點發生。

一個知名的例子便是太平洋火環(Pacific Ring of Fire)。根據美國國家海洋與大氣總署(NOAA)，這條25,000英哩長的環太平洋帶狀區域，因為含有成串的海底火山 (大約450座)和地震發生帶而為人所知。

在北美的太平洋海岸地區，火環經過從加拿大西岸延伸至美國西岸的卡斯卡迪亞(Cascadia)隱沒帶。據悉，大部分的地震都是沿著隱沒帶或是板塊內部的斷層發生。

然而，板塊實際上的定義為何以及板塊究竟有多厚，仍然是項爭議性十足的議題。這是因為雖然科學家知道板塊的頂部就是地球表面，但要界定板塊的底部卻相當困難。

近日由德拉瓦大學的Jessica Warren，和牛津大學與明尼蘇達大學雙城分校的科學家進行的研究，提出了全新的一組數據有助於科學家了解這項問題。

「知道板塊厚度為何對於暸解板塊運動的過程相當關鍵。板塊運動包括了板塊在中洋脊形成，以及隨後這些物質經由像卡斯卡迪亞、安地斯、日本及印尼附近的隱沒帶回到地球內部的過程。」德拉瓦大學地球、海洋與環境學院的地質科學系助理教授Warren表示。

「這也有助於科學家模擬並預測地震以及火山活動未來會造成的危害。依據模擬結果他們可以知道地震以及火山爆發可能的發生位置以及造成的破壞程度有多大。」

橄欖石：地球內部的穩健模型

由於要親臨現場研究地球內部是件不可能的事，因此當科學家企圖了解地球內部究竟發生何種事物時，他們必須另闢蹊徑。

科學家轉而研究地震波通過地球內部的過程，並將接收到的訊號反轉回去，以回推發生在地球內部的事物。另外，因為科學家知道地球內部比表層的地殼還要高溫，所以他們也能模擬岩石的熱學性質，包括地球內部發生溫度變化的位置。

「科學告訴我們對地球內部溫度變化的預測結果，應該要與地震波呈現給我們的一致。問題就是這兩種模型彼此之間並不吻合。」研究岩石來源和形成過程的岩石學專家Warren表示。

一項歷時已久的爭議是由地震波性質變化而辨識出的古氏不連續面(Gutenberg discontinuity)，是否可以代表板塊的底部。

為了探討這個問題，Warren和她的同僚在實驗室對橄欖石進行了試驗，這種礦物是在[岩石圈]地函(地球最上層250英哩厚的區域)中發現的主要礦物。橄欖石同時也是組成橄欖岩(peridotite)的主要礦物，科學家視橄欖岩為地球內部成分的穩健模型。

研究人員取用橄欖石並添加熔融物質(又稱玄武岩)，來模擬在中洋脊，新生板塊如何形成。團隊接著將橄欖石-熔融物質的混合物在高溫高壓之下扭轉，以測定熔融物質對橄欖岩晶體的排列方向會有什麼樣的影響。然後他們利用實驗結果，來推測地震波經過這類岩石後產生的訊號，並跟古氏不連續面的地震波訊號互相比較。

團隊的研究結果顯示古氏不連續面無法定義為板塊的底部。反之，古氏不連續面是因板塊內部含有橄欖石-融熔物質的混合物而產生。

「我已經研究橄欖岩中的橄欖石是如何排列10年以上，因為它們的流動模式可以做為一種歷史紀錄，從中可以得知這些從地函來的岩石如何隨著歲月移動及變形。」

研究人員的結果提出模擬板塊厚度的最佳方式，是依據溫度剖面，以及隨著板塊年齡增長由傳導造成的冷卻程度。

「我們認為板塊底部比溫度剖面中發生降溫之處還要更深。在地函內部有層岩石具有融熔物質或者在此凝固，改變了岩石的地震波性質，因而形成了我們看到的特殊層面，」她說。「經由我們的估算，這意味著海洋板塊的厚度大約為100公里，或是62英哩。」

Warren接著說明團隊得到的數據也可以用來說明古氏不連續面的成因，其等同於岩石在中洋脊融化之後，產生的熔融物質被包覆在岩石當中或者於岩石內部凝固的位置。當地震波經過此處時性質便會改變。

Tectonic shift? Study of olivine provides new data for measuring Earth's surface

Plate tectonics, the idea that the surface of the Earth is made up of plates that move apart and come back together, has been used to explain the locations of volcanoes and earthquakes since the 1960s.

One well-known example of this is the Pacific Ring of Fire, a 25,000-mile stretch of the Pacific Ocean known for its string of underwater volcanoes (nearly 450 of them) and earthquake sites, according to the National Oceanic and Atmospheric Administration (NOAA).

On the Pacific Coast, this area sits along the subduction zone known as the Cascadia plate, which runs down the west coast of Canada to the west coast of the United States. Most earthquakes are said to occur at subduction zones or along faults in tectonic plates.

What actually defines a tectonic plate and how thick plates are, however, has remained a hotly debated topic. This is because while scientists know that the top of the plate is the surface of the Earth, defining the plate's bottom boundary has been challenging.

A recent study by the University of Delaware's Jessica Warren and colleagues at the University of Oxford and the University of Minnesota, Twin Cities, provides a new data set that scientists can use to understand this problem.

「Understanding the thickness of the plate is important to understanding how plates move around, both when they form at mid-ocean ridges and later on when the material goes back down into the Earth through subduction zones such as those in Cascadia, the Andes, Japan and Indonesia," said Warren, assistant professor in the Department of Geological Sciences in the College of Earth, Ocean, and Environment.

"It also can help scientists model and predict future earthquake and volcanic hazards, where they might occur and how deep the devastation might be depending on what the models show."

Olivine a robust model of Earth's interior

To understand what's happening inside the Earth, scientists must be creative because studying the interior of the Earth in situ is impossible.

Instead, scientists study how seismic waves pass through the Earth and then invert the signal that is received to reverse engineer what's happening. They also model the thermal properties of the rock, including where temperature changes occur, because they know that the interior of the Earth is hotter than the surface crust.

"Science has been telling us that what we predict for temperature changes within the Earth should agree with what the seismic waves are telling us. The problem has been that these two models don't agree," said Warren, a petrology expert who studies the origin of rocks and how they formed.

One longstanding argument has been whether the Gutenberg discontinuity -- the identification of a change in seismic properties -- represents the bottom of the plate.

To investigate this problem, Warren and her colleagues performed laboratory experiments on olivine, the main mineral found in the Earth's mantle (the upper ~250 miles of the planet). Olivine also is the main mineral in peridotite rock, which is considered to be a robust model of the interior of the Earth's composition.

The researchers took olivine and added melt (also known as basalt) to mimic how a new plate is created at a mid-ocean ridge. The team then twisted the olivine-melt mixture under high temperatures and high pressure to determine the influence of melt on the alignment of olivine crystals. They then used these experiments to predict the seismic signature of this rock and compared it to the seismic signature associated with the Gutenberg discontinuity.

The team's results showed that the Gutenberg discontinuity does not define the bottom of the plate, but instead is caused by the presence of olivine-melt mixtures within tectonic plates.

"I've spent over a decade studying how olivine minerals are oriented in peridotite rocks because the flow patterns provide a historical record of how these rocks from the mantle have changed and deformed over time," says Warren.

The research team's results suggest the best way to model the plate thickness is based on the thermal profile and the conductive cooling that occurs as a plate ages.

"We think that the bottom of the plate is below where you have a cooling in the temperature profile. It is a layer that is associated with melt being trapped or frozen in the rock and changing the seismic properties in the rock that subsequently produced the layer that we're imaging," she said. "By our estimates, this would mean that the tectonic plates in the ocean are approximately 100 kilometers or about 62 miles thick. "

The team's data also offers an explanation for the Guttenberg discontinuity, Warren continued, saying that it corresponds to melt that was trapped or frozen in the rock after melting at mid-ocean ridges, which produced a change in how the seismic waves pass through the rock.

原始論文：Lars N. Hansen, Chao Qi, Jessica M. Warren. Olivine anisotropy suggests Gutenberg discontinuity is not the base of the lithosphere. Proceedings of the National Academy of Sciences, 2016; 113 (38): 10503 DOI: 10.1073/pnas.1608269113

引用自：University of Delaware. "Tectonic shift? Study of olivine provides new data for measuring Earth's surface." ScienceDaily. ScienceDaily, 15 December 2016. 

讓人難得有機會一窺留有羽毛的恐龍尾巴樣貌的琥珀樣品

原文網址：www.sciencedaily.com/releases/2016/12/161208141637.htm

讓人難得有機會一窺留有羽毛的恐龍尾巴樣貌的琥珀樣品

中國、加拿大和布里斯托大學的研究人員發現一條恐龍尾巴和上頭的羽毛被完整地封存在一塊琥珀當中

發表於《當代生物學》( Current Biology)上的這篇研究有助於填補恐龍羽毛構造及演化上的細節，這是難以從化石證據中推論出來的。

研究人員表示雖然並非首度在琥珀中發現羽毛，但之前的樣本卻很難十分肯定地說明它們來自於何種動物。

加拿大薩斯喀徹爾皇家博物館的Ryan McKellar表示：「這塊新樣本保存了一條動物幼體尾巴中的八塊脊椎骨，分佈於周遭的羽毛保留了立體構造與細微結構。」

「我們可以肯定地說這條尾巴來自於哪種動物，因為內部的脊椎骨並未像現代鳥類或者牠們關係最近的親戚一樣融合成一根骨頭，也就是尾縱骨(pygostyle)。反之，這條尾巴長度很長且可以自由彎曲，兩側垂有成排的羽毛。換句話說，這些羽毛必定來自於一種恐龍，而非史前鳥類。」

2015年，來自北京中國地質大學的研究第一作者Lida Xing，在緬甸密支那的琥珀市場中發現了這件獨一無二的樣品。

原本認為這塊琥珀中包裹的是某種植物，並預計要把它拿來打造成一具珠寶或珍玩，但Xing認出它可能具有重大的科學價值，而建議德煦古生物研究所買下這具樣品。

研究人員表示這具樣本為9900萬年前一隻獸腳亞目的恐龍，其留有羽毛的尾巴保存在白堊紀中期的琥珀當中。雖然起初很難辨認琥珀內含物質的細節，但Xing和他的同僚借助電腦斷層掃瞄，以及顯微鏡觀察而得以看見細部構造。

羽毛顯示出這條尾巴的表面呈現栗棕色，而底面則為灰白色。此樣品也對羽毛的演化有所啟發。這些羽毛缺乏一根發育完整的主軸，或稱羽軸(rachis)。它們的構造也指出現代羽毛當中最細微的兩級構造，也就是羽枝(barb)和小羽枝(barbule)，形成的時間早於羽軸。

布里斯托大學地球科學院的教授Mike Benton補充：「這項研究的驚人之處在於能夠看到一條恐龍尾巴上的所有細節，包含骨頭、肌肉、皮膚以及羽毛；並且可以想像這隻小傢伙的尾巴被樹液黏住，之後可能因為無法脫困而死亡。」

「我們不認為恐龍跟現在的某些蜥蜴一樣能夠斷尾求生。」

研究人員也檢視了包覆在其中的尾巴暴露在琥珀表面處的化學性質。分析結果顯示骨頭周遭的軟組織層含有些微的亞鐵離子，此為同樣包在樣品中的血紅素遺留下來的痕跡。

這項發現顯示琥珀具有可以用來補足化石紀錄的重要價值。Ryan McKellar補充：「雖然琥珀碎片僅能保存古代生態系的隻字片語，但是它們可以記錄生物的細微構造、其立體排列方式以及容易腐敗的部分，這些是很難用其他類型的樣品來研究的。」

「琥珀這種新資訊來源值得人們加以大力研究，而且應該被視為一種化石資源而多加保護。」

研究人員表示他們現在「十分期待看到這個地區將來還會有更多發現，可以重新塑造我們對恐龍以及其他脊椎動物身上羽毛和軟組織的認識。」

Amber specimen offers rare glimpse of feathered dinosaur tail

Researchers from China, Canada, and the University of Bristol have discovered a dinosaur tail complete with its feathers trapped in a piece of amber.

The finding reported today in Current Biology helps to fill in details of the dinosaurs' feather structure and evolution, which can't be surmised from fossil evidence.

While the feathers aren't the first to be found in amber, earlier specimens have been difficult to definitively link to their source animal, the researchers say.

Ryan McKellar, from the Royal Saskatchewan Museum in Canada, said: "The new material preserves a tail consisting of eight vertebrae from a juvenile; these are surrounded by feathers that are preserved in 3D and with microscopic detail.

"We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives. Instead, the tail is long and flexible, with keels of feathers running down each side. In other words, the feathers definitely are those of a dinosaur not a prehistoric bird."

The study's first author Lida Xing from the China University of Geosciences in Beijing discovered the remarkable specimen at an amber market in Myitkyina, Myanmar in 2015.

The amber piece was originally seen as some kind of plant inclusion and destined to become a curiosity or piece of jewellery, but Xing recognized its potential scientific importance and suggested the Dexu Institute of Palaeontology buy the specimen.

The researchers say the specimen represents the feathered tail of a theropod preserved in mid-Cretaceous amber about 99 million years ago. While it was initially difficult to make out details of the amber inclusion, Xing and his colleagues relied on CT scanning and microscopic observations to get a closer look.

The feathers suggest the tail had a chestnut-brown upper surface and a pale or white underside. The specimen also offers insight into feather evolution. The feathers lack a well-developed central shaft or rachis. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before a rachis formed.

Professor Mike Benton from the School of Earth Sciences at the University of Bristol, added: "It's amazing to see all the details of a dinosaur tail -- the bones, flesh, skin, and feathers -- and to imagine how this little fellow got his tail caught in the resin, and then presumably died because he could not wrestle free.

"There's no thought that dinosaurs could shed their tails, as some lizards do today."

The researchers also examined the chemistry of the tail inclusion where it was exposed at the surface of the amber. The analysis shows that the soft tissue layer around the bones retained traces of ferrous iron, a relic left over from haemoglobin that was also trapped in the sample.

The findings show the value of amber as a supplement to the fossil record. Ryan McKellar added: "Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings.

"This is a new source of information that is worth researching with intensity, and protecting as a fossil resource."

The researchers say they are now "eager to see how additional finds from this region will reshape our understanding of plumage and soft tissues in dinosaurs and other vertebrates."

原始論文：Lida Xing, Ryan C. McKellar, Xing Xu, Gang Li, Ming Bai, W. Scott Persons IV, Tetsuto Miyashita, Michael J. Benton, Jianping Zhang, Alexander P. Wolfe, Qiru Yi, Kuowei Tseng, Hao Ran, Philip J. Currie. A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber. Current Biology, 2016; DOI: 10.1016/j.cub.2016.10.008

引用自：University of Bristol. "Amber specimen offers rare glimpse of feathered dinosaur tail." ScienceDaily. ScienceDaily, 8 December 2016.