title: Melanin concentration gradients in modern and fossil feathers.
abstract: In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ∼55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly related groups that share aquatic ecologies (e.g. waterfowl Anseriformes, penguins Sphenisciformes), suggesting a potential adaptive function with ancient origins.
authors.affiliation: Department of Geology and Geophysics, Yale University, New Haven, Connecticut, United States of America. daniel.field@yale.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Field
authors.forename: Liliana
authors.initials: L
authors.lastname: D'Alba
authors.forename: Jakob
authors.initials: J
authors.lastname: Vinther
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Webb
authors.forename: William
authors.initials: W
authors.lastname: Gearty
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Shawkey
mesh_terms: D000818:Animals; D001717:Birds / Q000033:anatomy & histology / Q000378:metabolism; D005241:Feathers / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism*; D005580:Fossils; D008543:Melanins / Q000378:metabolism*; D020460:Melanosomes / Q000378:metabolism; D010858:Pigmentation
chemical_list: D008543:Melanins
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