Feather diversity in the Barremian (Early Cretaceous) of Las Hoyas, Spain. 2011. J. Marugan-Lobon and R. Vullo. Comptes Rendus Palevol 10: 219-223.
Abstract: The preservation of feathers is a rare phenomenon in the fossil record. In this study, we report 11 isolated feathers from the Early Cretaceous of the Konservat-Lagerstätte of Las Hoyas, Spain. Most of them are preserved as a carbonised thin layer, but there are also imprints. The specimens are relatively small, and unambiguously correspond to body contour feathers, although it is very difficult to match them to a particular taxon (among avian or non-avian theropods).
Among the fossils, there is an almost complete remige, a well-preserved fragment of a possible ornamental rectrice feather, and possibly a semiplume. Furthermore, some specimens appear to have different colour patterns, such as stripes or patches.