Cretaceous feather from the Upper Cretaceous (lower Campanian) Point Lookout Sandstone, San Juan Basin, northwestern New Mexico
ABSTRACT Fossils of Cretaceous feathers are extremely rare, especially from clastic sediments. Here we report on a partial pennaceous feather collected from the lower Campanian Point Lookout Sandstone of northwestern New Mexico (New Mexico Museum of Natural History locality L-7468). The feather is from a laterally discontinuous shale at the top of the Point Lookout Sandstone, a basal marine shoreline facies deposited during the R-4 regressive cycle. The shale contains cylindrical invertebrate burrows including Ophiomorpha, abundant plant fragments of conifers and angiosperms, and a sparse invertebrate fauna including the inarticulate brachiopod Lingula and the bivalves Caryocorbula and Nucula.The partial pennaceous feather, University of New Mexico (UNM) 14742, is preserved on a bedding plane as either a carbonized trace or an autolithification. The feather is missing the basal barbs and the base of the rachis and calamus. It possesses numerous barbs that are arrayed in symmetrical vanes. The vanes decrease in width toward a rounded tip. Both vanes show gaps that indicate the barbs normally interlocked and so possessed differentiated distal and proximal barbules. Based on this morphology, UNM 14742 is a closed pennaceous feather (Stage IV) and a contour feather and can be referred to Maniraptora, a group that includes true birds and coelurosaur dinosaurs.
Article: Fossilization of feathers[show abstract] [hide abstract]
ABSTRACT: Scanning electron microscopy of feathers has revealed evidence that a bacterial glycocalyx (a network of exocellular polysaccharide fibers) played a role in promoting their fossilization in some cases. This mode of preservation has not been reported in other soft tissues. The majority of fossil feathers are preserved as carbonized traces. More rarely, bacteria on the surface are replicated by authigenic minerals (bacterial autolithification). The feathers of Archaeopteryx are preserved mainly by imprintation following early lithification of the substrate and decay of the feather. Lacustrine settings provide the most important taphonomic window for feather preservation. Preservation in terrestrial and normal-marine settings involves very different processes (in amber and in authigenically mineralized coprolites, respectively). Therefore, there may be a significant bias in the avian fossil record in favor of inland water habitats.Geology. 01/1995; 23(9).
- Proceedings of The Royal Society of London. 01/1887; 43:165-171.
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ABSTRACT: A fossil feather preserved as a carbonised trace is described from the Tomaj Limestone at Križ, in the Kras region of southwestern Slovenia. The Tomaj Limestone is a platy and laminated limestone with cherts, which occurs within a well-bedded rudist limestone of the Santonian–Campanian Lipica Formation. It was deposited in a lagoon environment and has yielded a diverse fossil assemblage. Whether this feather belonged to a bird or to a dinosaur is unclear, but it is an addition to the scanty record of Late Cretaceous feathers, from a palaeobiogeographically interesting area.01/2002;