Researchers report radiogenic ages for the deposition of the earliest fossil-bearing sedimentary rocks of the Huajiying Formation in northern China, which contains bird fossils representing early avian evolutionary radiation and associated vertebrates comprising the early phase of the evolution of the early Cretaceous Jehol Biota; the ages constrain the onset of the biota, which contains exceptionally preserved feathered dinosaurs, early birds, mammals, insects, and early flowering plants, to around 135 million years ago and its duration to around 15 million years, according to the authors.
Article #19-18272: "The appearance and duration of the Jehol Biota: Constraint from SIMS U-Pb zircon dating for the Huajiying Formation in northern China," by Saihong Yang et al.
MEDIA CONTACT: Zhonghe Zhou, Chinese Academy of Sciences, Beijing, CHINA; e-mail: zhouzhonghe@ivpp.ac.cn
###
Proceedings of the National Academy of Sciences