Molecular composition and ultrastructure of Jurassic paravian feathers
Johan Lindgren, Peter Sjövall, Ryan M. Carney, Aude Cincotta, Per Uvdal, Steven W. Hutcheson, Ola Gustafsson, Ulysse Lefèvre, François Escuillié, Jimmy Heimdal, Anders Engdahl, Johan A. Gren, Benjamin P. Kear, Kazumasa Wakamatsu, Johan Yans & Pascal Godefroit
Scientific Reports 5, Article number: 13520 (2015)
doi:10.1038/srep13520
Received:
10 April 2015
Accepted:
29 July 2015
Published online:
27 August 2015
Abstract
Feathers are amongst the most complex epidermal structures known, and they have a well-documented evolutionary trajectory across non-avian dinosaurs and basal birds. Moreover, melanosome-like microbodies preserved in association with fossil plumage have been used to reconstruct original colour, behaviour and physiology. However, these putative ancient melanosomes might alternatively represent microorganismal residues, a conflicting interpretation compounded by a lack of unambiguous chemical data. We therefore used sensitive molecular imaging, supported by multiple independent analytical tests, to demonstrate that the filamentous epidermal appendages in a new specimen of the Jurassic paravian Anchiornis comprise remnant eumelanosomes and fibril-like microstructures, preserved as endogenous eumelanin and authigenic calcium phosphate. These results provide novel insights into the early evolution of feathers at the sub-cellular level, and unequivocally determine that melanosomes can be preserved in fossil feathers.
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Uma pergunta causticante:
Pode isso, Arnaldo?
A regra é clara - pigmentos não podem durar todos esses milhões de anos.
Ora se o pigmento em penas fossilizadas não podem durar 150 milhões de anos, quer dizer então que a estória da evolução dos dinossauros a partir de aves está errada? Pano rápido!
