對被認為僅僅含有一只有翼恐龍的羽毛痕跡的化石的重新檢查可能顯示出把鳥類和恐龍聯(lián)系起來的羽毛殘余。Roy Wogelius及其同事用極化X射線為已知最早的鳥類——始祖鳥的化石拍照,，并生成了這一化石的高分辨率化學(xué)圖,。始祖鳥顯示出了和鳥類（羽毛）與恐龍（牙齒）共有的特征。
這組科學(xué)家使用了一種同步輻射X射線裝置,，用強烈但是非損傷性的X射線掃描這個樣本,，從而分析它的結(jié)構(gòu)和化學(xué)成分。這項檢查顯示出這些羽毛的元素組成不同于周圍的巖石,，這表明石化羽毛物質(zhì)的殘余仍然存在于這個標本中,。這項發(fā)現(xiàn)與此前的分析相反。此前的分析得出結(jié)論認為這種鳥的可見羽毛僅僅是壓痕,。
這些化學(xué)圖可能提供這種動物的石化與保存是如何發(fā)生的線索,，并為這一化石在發(fā)現(xiàn)之后的歷史提供見解。這組作者說,，這種技術(shù)還可能促進生物分子提取,、檢驗造假等學(xué)科，還能促進對古代文件的檢驗,。（生物谷Bioon.com）
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.1001569107
Archaeopteryx feathers and bone chemistry fully revealed via synchrotron imaging
U. Bergmanna, R. W. Mortonb, P. L. Manningc,d, W. I. Sellerse, S. Farrarf, K. G. Huntleyb, R. A. Wogeliusc,g,1, and P. Larsonc,f
aStanford Linear Accelerator Center National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, CA 94025;
bChildren of the Middle Waters Institute, Bartlesville, OK, 74003;
cSchool of Earth, Atmospheric, and Environmental Sciences, University of Manchester, Manchester, M13 9PL, United Kingdom;
dDepartment of Earth and Environmental Sciences, University of Pennsylvania, Philadelphia, PA, 19104;
eFaculty of Life Sciences, University of Manchester, Manchester, M13 9PT, United Kingdom;
fBlack Hills Institute of Geological Research, Inc., Hill City, SD, 57745; and
gWilliamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester, M13 9PL, United Kingdom
Evolution of flight in maniraptoran dinosaurs is marked by the acquisition of distinct avian characters, such as feathers, as seen in Archaeopteryx from the Solnhofen limestone. These rare fossils were pivotal in confirming the dinosauria-avian lineage. One of the key derived avian characters is the possession of feathers, details of which were remarkably preserved in the Lagerst?tte environment. These structures were previously simply assumed to be impressions; however, a detailed chemical analysis has, until now, never been completed on any Archaeopteryx specimen. Here we present chemical imaging via synchrotron rapid scanning X-ray fluorescence (SRS-XRF) of the Thermopolis Archaeopteryx, which shows that portions of the feathers are not impressions but are in fact remnant body fossil structures, maintaining elemental compositions that are completely different from the embedding geological matrix. Our results indicate phosphorous and sulfur retention in soft tissue as well as trace metal (Zn and Cu) retention in bone. Other previously unknown chemical details of Archaeopteryx are also revealed in this study including: bone chemistry, taphonomy (fossilization process), and curation artifacts. SRS-XRF represents a major advancement in the study of the life chemistry and fossilization processes of Archaeopteryx and other extinct organisms because it is now practical to image the chemistry of large specimens rapidly at concentration levels of parts per million. This technique has wider application to the archaeological, forensic, and biological sciences, enabling the mapping of “unseen” compounds critical to understanding biological structures, modes of preservation, and environmental context.
