加拿大琥珀 發現恐龍羽毛化石

加拿大博物館的收藏品中，發現少量封存在琥珀中的羽毛化石，年代溯自8000萬年前的恐龍或鳥類。

加拿大亞伯達大學（University of Alberta）研究生邁凱拉（Ryan McKellar），曾仔細研究這所大學和皇家泰瑞爾古生物學博物館（Royal Tyrrell Museumof Palaeontology）所保存的4000多個琥珀樣本。

最後他發現11個保存著羽毛化石的珍貴琥珀樣本。他在「科學」（Science）期刊所發表的研究報告中，說這些樣本「是白堊紀晚期的琥珀羽毛化石」，年代可以追溯到6500到9900萬年前。

白堊紀最為人所知的是，最後陸地與海洋物種大規模滅絕，也是恐龍消失的時候。

邁凱拉所發現的化石，顏色從褐色到黑色都有，保存在樹脂內，後來變成琥珀，是從加拿大西南部亞伯達省草湖（Grassy Lake）附近知名的琥珀沉積岩層中出土。

Coiled For DivingA feather accompanied by a microphysid plant bug. The coiling observed in the feather is directly comparable to coils found in modern bird feathers specialized for water uptake and are suggestive of diving behavior, but similar structures can be used to transport water to the nest.

Simple ProtofeathersNumerous individual filaments in Late Cretaceous Canadian amber. These filaments are similar to the protofeathers that have been found as fossils with some dinosaurs. These filaments range from clear to near-black. 

Pigmented FeathersOverview of 16 clumped feather barbs

Simple PigmentsOverview of 6 pigmented feather barbs.

A clear exampleAn isolated, unpigmented feather barb and a mite preserved in Canadian Late Cretaceous amber.

Color-Producing CellsA feather barb that shows some indication of original coloration. The oblong brown masses within the image are regions of color within the barbules. In this specimen, the overall feather color appears to have been medium- or dark-brown. 

Modern EquivalentAn isolated barb from a white belly feather of a modern grebe (Aechmophorus occidentalis), illustrating coiled barbule bases comparable to those in the Cretaceous specimen. In both cases, the coiling is a structural adaptation that allows the feather to absorb water. 

Curly CoilsThe cork-screw shaped structures in the image are the tightly coiled bases of feather barbules.

Brown FeathersPigmentation in these feathers gives it a beaded appearance. Pigment in the feather suggests it would have been medium- or dark-brown in color.