the completeness of the fossil record of mesozoic birds implications for early avian evolution中生代鸟类的化石记录的完整性对早期鸟类进化的影响.pdf

The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution 1 2 1,3 4,5 Neil Brocklehurst *, Paul Upchurch , Philip D. Mannion , Jingmai O’Connor ¨ ¨ ¨ 1 Museum fur Naturkunde, Leibniz-Institut fur Evolutions und Biodiversitatsforschung, Berlin, Germany, 2 Department of Earth Sciences, UCL, London, United Kingdom, 3 Department of Earth Science and Engineering, Imperial College London, London, United Kingdom, 4 Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China, 5 Dinosaur Institute, Natural History Museum of LA County, Los Angeles, California, United States of America Abstract Many palaeobiological analyses have concluded that modern birds (Neornithes) radiated no earlier than the Maastrichtian, whereas molecular clock studies have argued for a much earlier origination. Here, we assess the quality of the fossil record of Mesozoic avian species, using a recently proposed character completeness metric which calculates the percentage of phylogenetic characters that can be scored for each taxon. Estimates of fossil record quality are plotted against geological time and compared to estimates of species level diversity, sea level, and depositional environment. Geographical controls on the avian fossil record are investigated by comparing the completeness scores of species in different continental regions and latitudinal bins. Avian fossil record quality varies greatly with peaks during the Tithonian-early Berriasian, Aptian, and Coniacian–Santonian, and troughs during the Albian-Turonian and the Maastrichtian. The completeness metric correlates more strongly with a ‘sampling corrected’ residual diversity curve of