Animal Flight Laboratory, Department of Evolutionary and Environmental Biology and the Institute of Evolution, University of Haifa, Haifa 3498838, Israel; The Nili & David Jerusalem Bird Observatory (JBO), Israel Ornithological Center, Society for the Protection of Nature in Israel, Jerusalem, Israel.
The Nili & David Jerusalem Bird Observatory (JBO), Israel Ornithological Center, Society for the Protection of Nature in Israel, Jerusalem, Israel.
Curr Biol. 2020 Sep 21;30(18):3633-3638.e2. doi: 10.1016/j.cub.2020.06.046. Epub 2020 Jul 16.
Feather molt is an important life-history process in birds, but little is known about its evolutionary history. Here, we report on the first fossilized evidence of sequential wing feather molt, a common strategy among extant birds, identified in the Early Cretaceous four-winged dromaeosaurid Microraptor. Analysis of wing feather molt patterns and ecological properties in extant birds imply that Microraptor maintained its flight ability throughout the entire annual cycle, including the molt period. Therefore, we conclude that flight was essential for either its daily foraging or escaping from predators. Our findings propose that the development of sequential molt is the outcome of evolutionary forces to maintain flight capability throughout the entire annual cycle in both extant birds and non-avialan paravian dinosaurs from 120 mya. VIDEO ABSTRACT.
羽毛换羽是鸟类生命周期中的一个重要过程，但关于其进化历史知之甚少。在这里，我们报告了首例在早白垩世四翼驰龙类小盗龙中发现的、顺序性翼羽换羽的化石证据，这是现生鸟类中常见的策略。对现生鸟类的翼羽换羽模式和生态特性的分析表明，小盗龙在整个年度周期中，包括换羽期，都保持了飞行能力。因此，我们得出结论，飞行对于其日常觅食或逃避捕食者至关重要。我们的研究结果表明，顺序性换羽的发展是为了在 1.2 亿年前的现生鸟类和非鸟兽脚类恐龙中，在整个年度周期中保持飞行能力的进化力量的结果。
