Beijing Museum of Natural History, 126 Tianqiao South Street, Beijing 100050, People's Republic of China.
Science. 2012 Mar 9;335(6073):1215-9. doi: 10.1126/science.1213780.
Iridescent feather colors involved in displays of many extant birds are produced by nanoscale arrays of melanin-containing organelles (melanosomes). Data relevant to the evolution of these colors and the properties of melanosomes involved in their generation have been limited. A data set sampling variables of extant avian melanosomes reveals that those forming most iridescent arrays are distinctly narrow. Quantitative comparison of these data with melanosome imprints densely sampled from a previously unknown specimen of the Early Cretaceous feathered Microraptor predicts that its plumage was predominantly iridescent. The capacity for simple iridescent arrays is thus minimally inferred in paravian dinosaurs. This finding and estimation of Microraptor feathering consistent with an ornamental function for the tail suggest a centrality for signaling in early evolution of plumage and feather color.
许多现存鸟类展示中的虹彩羽毛颜色是由含有黑色素的细胞器（黑素体）的纳米级阵列产生的。与这些颜色的进化以及产生它们所涉及的黑素体的特性相关的数据一直很有限。一个抽样研究现存鸟类黑素体变量的数据集表明，形成最具虹彩效果的黑素体明显较窄。对这些数据与之前未知的白垩纪早期有羽毛的小盗龙的黑素体印痕进行的定量比较预测，它的羽毛主要是虹彩的。因此，在兽脚亚目恐龙中，简单的虹彩排列能力是最小的。这一发现和对小盗龙羽毛的估计与尾巴的装饰功能一致，表明在羽毛和羽毛颜色的早期进化中信号传递具有核心地位。
