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Phase Contrast X-Ray Synchrotron Imaging: Opening Access to Fossil Inclusions in Opaque Amber

  • Malvina Lak (a1) (a2), Didier Néraudeau (a2), André Nel (a3), Peter Cloetens (a1), Vincent Perrichot (a4) and Paul Tafforeau (a1) (a5)...

A significant portion of Mesozoic amber is fully opaque. Biological inclusions in such amber are invisible even after polishing, leading to potential bias in paleoecological and phylogenetic studies. Until now, studies using conventional X-ray microtomography focused on translucent or semi-opaque amber. In these cases, organisms of interest were visualized prior to X-ray analyses. It was recently demonstrated that propagation phase contrast X-ray synchrotron imaging techniques are powerful tools to access invisible inclusions in fully opaque amber. Here we describe an optimized synchrotron microradiographic protocol that allowed us to investigate efficiently and rapidly large amounts of opaque amber pieces from Charentes (southwestern France). Amber pieces were imaged with microradiography after immersion in water, which optimizes the visibility of inclusions. Determination is not accurate enough to allow precise phylogenetic studies, but provides preliminary data on biodiversity and ecotypes distribution; phase contrast microtomography remains necessary for precise determination. Because the organisms are generally much smaller than the amber pieces, we optimized local microtomography by using a continuous acquisition mode (sample moving during projection integration). As tomographic investigation of all inclusions is not practical, we suggest the use of a synchrotron for a microradiographic survey of opaque amber, coupled with microtomographic investigations of the most valuable organisms.

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Baruchel, J., Lodini, A., Romanzetti, S., Rustichelli, F. & Scrivani, A. (2001). Phase-contrast imaging of thin biomaterials. Biomater 22, 15151520.
Beckmann, F., Bonse, U., Busch, F. & Günnewig, O. (1997). X-ray microtomography (μCT) using phase contrast for the investigation of organic matter. J Comput Assist Tomogr 21, 539553.
Cloetens, P., Barrett, R., Baruchel, J., Guigay, J.-P. & Schlenker, M. (1996a). Phase objects in synchrotron radiation hard X-ray imaging. J Phys D Appl Phys 29, 133146.
Cloetens, P., Ludwig, W., Baruchel, J., Guigay, J.-P., Pernot-Rejmánková, P., Salomé-Pateyron, M., Schlenker, M., Buffières, J.-Y., Maire, E. & Peix, G. (1996b). Hard X-ray phase imaging using simple propagation of a coherent synchrotron radiation beam. J Phys D Appl Phys 32, A145A151.
Cnudde, V., Bosselaers, J., Masschaele, B., Vlassenbroeck, J., Dierick, M., Van Hoorebeke, L. & Jacobs, P. (2006). Species description of fossil spiders supported by non-destructive high-resolution X-ray CT. Geophys Res Abs 8, 08351.
Dierick, M., Cnudde, V., Masschaele, B., Vlassenbroeck, J., Van Hoorebeke, L. & Jacobs, P. (2007). Micro-CT of fossils preserved in amber. Nucl Instrum Methods A 580, 641643.
Grimaldi, D., Nguyen, T. & Ketcham, R. (2000). Ultra-high-resolution X-ray computed tomography (UHR CT) and the study of fossils in amber. In Studies on Fossils in Amber, with Particular References to the Cretaceous of New Jersey, D. Grimaldi (Ed.), pp. 7791. Leiden, The Netherlands: Backhuys Publishers.
Henderickx, H., Cnudde, V., Masschaele, B., Dierick, M., Vlassenbroeck, J. & Van Hoorebeke, L. (2006). Description of a new fossil Pseudogarypus (Pseudoscorpiones: Pseudogarypidae) with the use of X-ray micro CT to penetrate opaque amber. Zootaxa 1305, 4150.
Hennig, W. (1971). Insektenfossilien aus der unteren Kreide. III. Empidiformia (“Microphorinae”) aus der unteren Kreide und aus dem Baltischen Bernstein; ein Vertreter der Cyclorrhapha aus der untere Kreide. Stuttgarter Beiträge zur Naturkunde (B) 232, 128.
Momose, A. (1995). Demonstration of phase-contrast X-ray computed tomography using an X-ray interferometer. Nucl Instrum Methods Phys Res A 352, 622628.
Néraudeau, D., Allain, R., Perrichot, V., Videt, B., De Lapparent de Broin, F., Guillocheau, F., Phillippe, M., Rage, J.C. & Vullo, R. (2003). Découverte d'un dépôt paralique à bois fossiles, ambre insectifère et restes d'Iguanodontidae (Dinosauria, Ornithopoda) dans le Cénomanien inférieur de Fouras (Charente-Maritime, Sud-Ouest de la France). C R Palevol 2, 221230.
Néraudeau, D., Perrichot, V., Colin, J.P., Girard, V., Gomez, B., Guillocheau, F., Masure, E., Peyrot, D., Tostain, F., Videt, B. & Vullo, R. (2008). A new amber deposit from the cretaceous (uppermost Albian-lowermost Cenomanian) of SW France. Cretaceous Res., in press.
Néraudeau, D., Perrichot, V., Dejax, J., Masure, E., Nel, A., Philippe, M., Moreau, P., Guillocheau, F. & Guyot, T. (2002). Un nouveau gisement à ambre insectifère et à végétaux (Albien terminal probable): Archingeay (Charente-Maritime, France). Geobios 35, 233240.
Perrichot, V. (2004). Early cretaceous amber from south-western France: Insight into the Mesozoic litter fauna. Geologica Acta 2, 922.
Perrichot, V. (2005). Environnements paraliques à ambre et à végétaux du Crétacé nord-aquitain (Charentes, Sud-Ouest de la France). Mémoires de Géosciences Rennes, 118, 310 pp.
Perrichot, V., Nel, A. & Néraudeau, D. (2007). Schizopterid bugs (Insecta: heteroptera) in mid-Cretaceous ambers from France and Myanmar (Burma). Palaeontology 50, 13671374.
Polcyn, M.J., Rogers, J.V. II, Kobayashi, Y. & Jacobs, L.L. (2003). Computed tomography of an Anolis lizard in dominican amber: Systematic, taphonomic, biogeographic, and evolutionary implications. Palaeontologia Electronica 5, 13 pp.
Snigirev, A., Snigireva, I., Kohn, V., Kuznetsov, S. & Schelokov, I. (1995). On the possibilities of X-ray phase contrast microimaging by coherent high-energy synchrotron radiation. Rev Sci Instrum 66, 54865492.
Tafforeau, P., Boistel, R., Boller, E., Bravin, A., Brunet, M., Chaimanee, Y., Cloetens, P., Feist, M., Hoszowska, J., Jaeger, J.-J., Kay, R.F., Lazzari, V., Marivaux, L., Nel, A., Nemoz, C., Thibault, X., Vignaud, P. & Zabler, S. (2006). Applications of X-ray synchrotron microtomography for non-destructive 3D studies of paleontological specimens. Appl Phys A Mater Sci Process 83, 195202.
Wilkins, S.W., Gureyev, T.E., Gao, D., Pogany, A. & Stevenson, A.W. (1996). Phase-contrast imaging using polychromatic hard X-rays. Nature 384, 335338.
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Microscopy and Microanalysis
  • ISSN: 1431-9276
  • EISSN: 1435-8115
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