Pterosaur melanosomes support signalling functions for early feathers

Nature, vol. 604, pp. 684–688

Abstract

Abstract Remarkably well-preserved soft tissues in Mesozoic fossils have yielded substantial insights into the evolution of feathers1. New evidence of branched feathers in pterosaurs suggests that feathers originated in the avemetatarsalian ancestor of pterosaurs and dinosaurs in the Early Triassic2, but the homology of these pterosaur structures with feathers is controversial3,4. Reports of pterosaur feathers with homogeneous ovoid melanosome geometries2,5suggest that they exhibited limited variation in colour, supporting hypotheses that early feathers functioned primarily in thermoregulation6. Here we report the presence of diverse melanosome geometries in the skin and simple and branched feathers of a tapejarid pterosaur from the Early Cretaceous found in Brazil. The melanosomes form distinct populations in different feather types and the skin, a feature previously known only in theropod dinosaurs, including birds. These tissue-specific melanosome geometries in pterosaurs indicate that manipulation of feather colour—and thus functions of feathers in visual communication—has deep evolutionary origins. These features show that genetic regulation of melanosome chemistry and shape7–9was active early in feather evolution.

Authors 11

1. Aude Cincotta corresponding

   University of Namur · University College Cork · Institute of Natural Sciences · Institute of Life, Earth and Environment

   Affiliation as printed

   Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium. acincotta@naturalsciences.be

   Environmental Research Institute, University College Cork, Cork, Ireland. acincotta@naturalsciences.be

   Institute of Life, Earth and Environment, University of Namur, Namur, Belgium. acincotta@naturalsciences.be

   School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland. acincotta@naturalsciences.be

   Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium

2. Michaël P. J. Nicolaï

   Ghent University

   Affiliation as printed

   Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium

3. Hebert Bruno Nascimento Campos

   Centro Universitário Maurício de Nassau

   Affiliation as printed

   Centro Universitário Maurício de Nassau, Campina Grande, Brazil

4. Maria E. McNamara corresponding

   University College Cork

   Affiliation as printed

   Environmental Research Institute, University College Cork, Cork, Ireland. maria.mcnamara@ucc.ie

   School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland. maria.mcnamara@ucc.ie

   School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland

5. Liliana D’Alba Aachen Naturalis Biodiversity Center

   Naturalis Biodiversity Center · Ghent University

   Affiliation as printed

   Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium

   Naturalis Biodiversity Center, Leiden, The Netherlands

6. Matthew D. Shawkey

   Ghent University

   Affiliation as printed

   Evolution and Optics of Nanostructures Group, Biology Department, Ghent University, Ghent, Belgium

7. Edio-Ernst Kischlat

   Serviço Geológico do Brasil - CPRM

   Affiliation as printed

   Divisão de Bacias Sedimentares, Geological Survey of Brazil, Porto Alegre, Brazil

8. Johan Yans

   University of Namur · Institute of Life, Earth and Environment

   Affiliation as printed

   Institute of Life, Earth and Environment, University of Namur, Namur, Belgium

9. Robert Carleer

   Hasselt University

   Affiliation as printed

   Research Group of Analytical and Circular Chemistry, Institute for Material Research, Hasselt University, Diepenbeek, Belgium

10. François Escuillié
    Affiliation as printed

    ELDONIA, Gannat, France

11. Pascal Godefroit

    Institute of Natural Sciences

    Affiliation as printed

    Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium