A non-destructive technique for chemical mapping of insect inclusions in amber
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Synchrotron-based techniques offer a wealth of elemental, molecular, and structural insights in biological samples, but the application of these techniques to fossils is a relatively new development. Here we examine how synchrotron radiation micro X-ray fluorescence (SR µXRF) may be used to investigate the chemical composition of insects trapped in amber, while leaving the inclusions unaltered. Elemental distribution data could provide important information on tissue preservation in insect inclusions, as well as information on the processes involved in fossilization. By analyzing a series of ants (Hymenoptera: Formicidae) that range from modern material, to Eocene Baltic amber, and Late Cretaceous North Carolina amber, we investigate how variable preservation influences the results obtained through SR µXRF analyses, as well as the various merits and pitfalls associated with the application of this technique to amber inclusions. This work serves as an introduction to the underlying principles, strengths, and limitations associated with applying SR µXRF in a palaeontological context.
KeywordsSynchrotron X-Ray fluorescence Fossil Preservation Formicidae Imaging
The authors would like to thank David Cooper, Isaac Pratt, and Kim Harrison (University of Saskatchewan) for their assistance in benchtop X-ray µCT scanning of amber inclusions in preparation for this project; thanks also go to Michael Engel (University of Kansas) and Victor Krynicki, for the access to the North Carolina ant specimens. We are also grateful for the valuable comments by Jörn Peckmann and one anonymous reviewer, with additions from editor-in-chief Mike Reich. The research described in this paper was performed at the CLS Anezka P. Kolaceke acknowledges the receipt of support from the CLS Graduate Student Travel Support Program and from the Faculty of Graduate Studies and Research at the University of Regina.
- Brun, R, and F. Rademakers. 1997. ROOT—an object oriented data analysis framework. Nuclear Instruments and Methods in Physics Research A 389: 81–86 (Proceedings AIHENP’96 Workshop, Lausanne, Sep. 1996) (see also http://root.cern.ch/).
- Clark, N.D., and C. Daly. 2010. Using confocal laser scanning microscopy to image trichome inclusions in amber. Journal of Paleontological Techniques 8: 1–7.Google Scholar
- Edgecombe, G.D., V. Vahtera, S.R. Stock, A. Kallonen, X. Xiao, A. Rack, and G. Giribet. 2012. A scolopocryptopid centipede (Chilopoda: Scolopendromorpha) from Mexican amber: synchrotron microtomography and phylogenetic placement using a combined morphological and molecular data set. Zoological Journal of the Linnean Society 166 (4): 768–786.CrossRefGoogle Scholar
- Edwards, N.P., H.E. Barden, B.E. Van Dongen, P.L. Manning, P.L. Larson, U. Bergmann, W.I. Sellers, and R.A. Wogelius. 2011. Infrared mapping resolves soft tissue preservation in 50 million year-old reptile skin. Proceedings of the Royal Society of London (B: Biological Sciences) 278 (1722): 3209–3218.CrossRefGoogle Scholar
- Grimaldi, D., E. Bonwich, M. Delannoy, and S. Doberstein. 1994. Electron microscopic studies of mummified tissues in amber fossils. American Museum Novitates 3097: 1–31.Google Scholar
- Grimaldi, D.A., and M.S. Engel. 2005. Evolution of the insects. New York: Cambridge University Press.Google Scholar
- Henderickx, H., J. Bosselaers, E. Pauwels, L. Van Hoorebeke, and M. Boone. 2013. X-ray micro-CT reconstruction reveals eight antennomeres in a new fossil taxon that constitutes a sister clade to Dundoxenos and Triozocera (strepsiptera: corioxenidae). Palaeontologia Electronica 16 (3): 16–31.Google Scholar
- Henwood, A. 1992b. Soft-part preservation of beetles in Tertiary amber from the Dominican Republic. Palaeontology 35 (4): 901–912.Google Scholar
- Hu, Y.F., I. Coulthard, D. Chevrier, G. Wright, R. Igarashi, A. Sitnikov, B.W. Yates, T.K. Hallin, T.K. Sham, and R. Reininger. 2010. Preliminary commissioning and performance of the soft X-ray micro-characterization beamline at the Canadian Light Source. AIP Conference Proceedings 1234: 343–346.CrossRefGoogle Scholar
- Kirejtshuk, A.G., D. Azar, P. Tafforeau, R. Boistel, and V. Fernandez. 2009. New beetles of Polyphaga (Coleoptera, Polyphaga) from Lower Cretaceous lebanese amber. Denisia 26: 119–130.Google Scholar
- Krynicki, V.E. 2013. Primitive ants (Hymenoptera: Sphecomyrminae) in the Campanian (Late Cretaceous) of North Carolina (USA). Life: The Excitement of Biology 1: 156–165.Google Scholar
- Schweitzer, M.H., W. Zheng, T.P. Cleland, M.B. Goodwin, M.B. Goodwin, E. Boatman, E. Theil, M.A. Marcus, and S.C. Fakra. 2013. A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time. Proceedings of the Royal Society of London (B: Biological Sciences) 281 (1775): 20132741.CrossRefGoogle Scholar
- Speranza, M., J. Wierzchos, J. Alonso, L. Bettuchi, A. Martín-González, and C. Ascaso. 2010. Traditional and new microscopy techniques applied to the study of microscopic fungi included in amber. Microscopy: Science, Technology, Application and Education 2: 1135–1145.Google Scholar
- Tafforeau, P., R. Boistel, E. Boller, A. Bravin, M. Brunet, Y. Chaimanee, P. Cloetens, M. Feist, J. Hoszowska, J.J. Jaeger, and R.F. Kay. 2006. Applications of X-ray synchrotron microtomography for non-destructive 3D studies of paleontological specimens. Applied Physics A 83 (2): 195–202.CrossRefGoogle Scholar
- Van de Kamp, T., S. Rolo, and T. Baumbach. 2014. Scanning the past—synchrotron X-ray microtomography of fossil wasps in amber. Entomologie heute 26: 151–160.Google Scholar
- Weitschat, W., and W. Wichard. 2010. Baltic amber. In Biodiversity of fossils in amber from the major world deposits, ed. D. Penney, 80–115. Manchester: Siri Scientific Press.Google Scholar