morphological and geochemical evidence of eumelanin preservation in the feathers of the early cretaceous bird, gansus yumenensis真黑素的形态和地球化学证据保存在白垩纪早期鸟类的羽毛,甘肃yumenensis.pdfVIP

Morphological and Geochemical Evidence of Eumelanin Preservation in the Feathers of the Early Cretaceous Bird, Gansus yumenensis 1 1 2 1,3 1 Holly E. Barden *, Roy A. Wogelius , Daqing Li , Phillip L. Manning , Nicholas P. Edwards , Bart E. van Dongen1 1 School of Earth Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester, United Kingdom, 2 Gansu Geological Museum, Lanzhou, People’s Republic of China, 3 Department of Earth and Environmental Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America Abstract Recent studies have shown evidence for the preservation of colour in fossilized soft tissues by imaging melanosomes, melanin pigment containing organelles. This study combines geochemical analyses with morphological observations to investigate the preservation of melanosomes and melanin within feathers of the Early Cretaceous bird, Gansus yumenensis. Scanning electron microscopy reveals structures concordant with those previously identified as eumelanosomes within visually dark areas of the feathers but not in lighter areas or sedimentary matrices. Fourier transform infrared analyses show different spectra for the feathers and their matrices; melanic functional groups appear in the feather including carboxylic acid and ketone groups that are not seen in the matrix. When mapped, the carboxylic acid group absorption faithfully replicates the visually dark areas of the feathers. Electron Paramagnetic Resonance spectroscopy of one specimen demonstrates the presence of organic signals but proved