2011 GSA Annual Meeting in Minneapolis (912 October 2011)
Paper No. 15-7
Presentation Time: 9:35 AM-9:55 AM

THE ORIGINAL COLORS OF FOSSIL MOTHS

MCNAMARA, Maria E.1, BRIGGS, Derek E.G.2, ORR, Patrick J.3, WEDMANN, Sonja4, NOH, Heeso5, and CAO, Hui5, (1) Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06520, maria.mcnamara@yale.edu, (2) Dept. of Geology and Geophysics & Peabody Museum of Natural History, Yale University, 210 Whitney Avenue, P.O. Box 208109, New Haven, CT 06520, (3) UCD School of Geological Sciences, University College Dublin, Belfield, Dublin, 4, Ireland, (4) Forschungsstation Grube Messel, Senckenberg Forschungsinstitut und Naturmuseum, Messel, D-64409, Germany, (5) Dept. of Applied Physics, Yale University, 401 Becton Center, 15 Prospect St, New Haven, 06520

Fossilization of soft tissues in exceptionally preserved fossils has the potential to aid reconstructions of the morphology and appearance of ancient organisms. Recent studies of fossil birds and dinosaurs show that preserved pigmentary microstructures in fossil feathers can be used to reconstruct the original coloration. Exceptionally preserved fossils can also exhibit evidence of structural color, which is generated by scattering of light by periodic variations in tissue nanostructure. Structural colors function primarily in communication and are widespread in nature today, but the feasibility of their being fossilized, and thus their fossil record, have received little attention. As a result, the evolution of structural coloration and its functions in animals is poorly understood. This is particularly significant for the Lepidoptera (butterflies and moths), which exhibit the most complex and diverse structural colors of any extant group. Here we report the preservation of structurally colored scales in fossil lepidopterans from the ~47 million-year-old Eocene Grube Messel oil shales (Germany) and reconstruct the original colors of their wings. Specimens exhibit bright, non-iridescent metallic hues which are generated by a multilayer reflector comprised of a stack of perforated laminae in the scale lumen; differently colored scales differ in their ultrastructure. The original colors were altered during fossilization but can be reconstructed based upon preserved ultrastructural detail. Coloration is brightest on the dorsal forewing surfaces, indicating a defensive function. This visual signal was enhanced by suppression of iridescence (change in hue with viewing angle) achieved by two different optical mechanisms: extensive perforation, and concave distortion, of the multilayer reflector. The fossils provide the first evidence for the function of structural color in the fossil record and confirm the feasibility of reconstructing color in non-metallic lepidopteran fossils.

2011 GSA Annual Meeting in Minneapolis (912 October 2011)
General Information for this Meeting
Session No. 15
New Ideas on Studying Exceptionally Preserved Fossils: What to Do Next?
Minneapolis Convention Center: Room 205CD
8:00 AM-12:00 PM, Sunday, 9 October 2011

Geological Society of America Abstracts with Programs, Vol. 43, No. 5, p. 53

© Copyright 2011 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.