The feathers of the dinosaur Microraptor may have been an iridescent black color, new findings suggest. In modern birds, iridescent feather colors are produced by arrays of “melanosomes,” which are organelles containing the dark pigment melanin. Quanguo Li and colleagues in China and the United States compared fossilized melanosomes from the paravian dinosaur Microraptor to those found in modern birds. (Paravian dinosaurs make up a subgroup of the two-legged theropods and include the bird lineage.) In the fossil feathers and in modern, iridescent ones, the melanosomes were particularly narrow and elongated. They were also arranged in a sheetlike, end-to-end orientation. These features indicate that at least some of Microraptor’s feathers were iridescent and black, the authors conclude. They further note that the fossil feathers included a set of long tail feathers that could have served an ornamental or signaling purpose, for attracting mates. Li and colleagues speculate that iridescent coloring may have helped in this regard, making the tail feathers even more eye-catching.
Article #13: "Reconstruction of Microraptor and the Evolution of Iridescent Plumage," by Q. Li; Q. Meng at Beijing Museum of Natural History in Beijing, China; K.-Q. Gao at Peking University in Beijing, China; J.A. Clarke; J. Vinther at University of Texas at Austin in Austin, TX; M.D. Shawkey; L. D’Alba at University of Akron in Akron, OH; R. Pei; M. Ellison; M.A. Norell at American Museum of Natural History in New York, NY; J. Vinther at Yale University in New Haven, CT.