A feather from the Upper Cretaceous (lower Campanian) Point Lookout Sandstone, San Juan Basin, northwestern New Mexico T.E. Williamson a, * , B.S. Kues b , G.S. Weissmann b , T.A. Stidham c , S.L. Yurchyk b a New Mexico Museum of Natural History and Science,1801 Mountain Road, NW, Albuquerque, NM 87104, USA b Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA c Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258, USA article info Article history: Received 26 February 2008 Accepted in revised form 7 October 2008 Available online 17 October 2008 Keywords: New Mexico Late Cretaceous Early Campanian Point Lookout Sandstone Pennaceous feather Maniraptora 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 north- western 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 inter- locked 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. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction Fossils of Cretaceous feathers are extremely rare, especially from clastic sediments. Previous reports of Cretaceous fossil feathers from North America are restricted to reports of several feathers from the Santonian Eutaw Formation of eastern Alabama (Knight et al., 2006; Knight and Bingham, 2007), feathers in amber from the Turonian Raritan Formation in New Jersey (Grimaldi and Case, 1995; Kellner, 2002), and a feather in amber from the Campanian Foremost Formation in Canada (Davis and Briggs, 1995; Kellner, 2002). Isolated feathers preserved in clastic sediments have been reported from the Cretaceous of Brazil (Kellner and Campos, 2000) and Slovakia (Buffetaut et al., 2002). Here we report on a partial pennaceous feather recovered from the lower Campanian Point Lookout Sandstone of northwestern New Mexico (Fig. 1). The feather was recovered from New Mexico Museum of Natural History (NMMNH) locality L-7468, from a laterally discontinuous shale at the top of the Point Lookout Sandstone. The Point Lookout Sandstone represents a basal marine facies deposited during the R-4 regressive cycle (Molenaar, 1983; Fig. 1B). This locality is towards the eastern end of the outcrop of the Point Lookout Sandstone, and its age, based on ammonites from the immediately underlying Mancos Shale, is early Campa- nian (Dyman et al., 1994, fig. 9; Nummedal, 2004, fig. 6). Near the ghost town of La Ventana the Point Lookout is partially deltaic in origin (Wright, 1986; Wright-Dunbar, 1992). The shale correlates to the top of Unit 14 of Wright-Dunbar (1992). At this site, located north of Wright-Dunbar’s section, this unit consists of more interbedded carbonaceous shale beds than at the location of her stratigraphic section. The thin (<1 m thick) shale of locality L-7468 is a medium-grey, highly fissile shale, with small encrustations of secondary gypsum on bedding planes and in small voids. Most of the volume of the shale is unfossiliferous and lacks evidence of finely comminuted organic material, but the unit does contain a sparse fossil assem- blage of low diversity. Cylindrical burrows filled with poorly rounded quartz sand grains, in some cases with dense concentra- tions of fine plant material, are moderately common. These burrows range up to 25 mm in diameter, are oriented vertically to obliquely, and extend down 10 cm or more into the shale unit from the bioturbated sandstone immediately above it. The rough, pebbled surface of some of these burrows indicate that they are Ophiomorpha. * Corresponding author. E-mail address: thomas.williamson@state.nm.us (T.E. Williamson). Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes 0195-6671/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2008.10.003 Cretaceous Research 30 (2009) 547–550