Credit: This image was created by K.G. Huntley from data produced at the Stanford Synchrotron Radiation Lightsource, located at the Department of Energy's SLAC National Accelerator Laboratory. This work was published today in Proceedings of National Academy of Science. Science Daily
U. Bergmann a, R. W. Morton b, P. L. Manning c,d, W. I. Sellers e, S. Farrar f, K. G. Huntley b, R. A. Wogelius c,g,1, and P. Larson c,f
-Author Affiliations
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
Communicated by Philip H. Bucksbaum, Stanford University, Menlo Park, CA, February 16, 2010 (received for review August 12, 2009)
Abstract
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 Lagerstätte 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 ThermopolisArchaeopteryx, 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 ofArchaeopteryx 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.
trace elements X-ray absorption spectroscopy
Footnotes
1To whom correspondence should be addressed. E-mail:Roy.wogelius@manchester.ac.uk.
Author contributions: U.B. and P.L. designed research; U.B., R.W.M., P.L.M., W.I.S., S.F., K.G.H., R.A.W., and P.L. performed research; U.B. contributed new reagents/analytic tools; U.B., W.I.S., and R.A.W. analyzed data; and U.B., R.W.M., P.L.M., W.I.S., S.F., K.G.H., R.A.W., and P.L. wrote the paper. U.B. supervised the synchrotron analyses; R.W.M. originally conceived the imaging of fossils and the Archaeopteryx via SRS-XRF at SSRL and coordinated the research project between SSRL and the Black Hills Institute; S.F. assisted in cell design; K.G.H. provided image processing; and P.L. conceived of analyzing Archaeopteryx via SRS-XRF and provided specimen access and curator expertise.
The authors declare no conflict of interest.
This article contains supporting information online at
1To whom correspondence should be addressed. E-mail:Roy.wogelius@manchester.ac.uk.
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