JONES, T. D.; RUBEN, J. A.; HAVNER, R. W.; FRIEDFELD, R. B.; GEIST, N. R.; Stephen F. Austin State University; Oregon State University; Stephen F. Austin State University; Stephen F. Austin State University; Sonoma State University: INVESTIGATION OF SUPPOSED FEATHERS OF DINOSAURS FROM CHINA

Feather fossilization generally involves autolithification of bacteria associated with feather decomposition. The lithified bacteria form a mold, which is then infilled after the feather decays. Thus, the presence of fossilized bacteria and/or their glycocalyces often facilitates an accurate identification of fossilized integumentary structures. We used scanning electron microscopy to analyze samples of integument from ornithodiran (pterosaur, dinosaur, and aves) fossils from Liaoning, China, to determine the presence or absence of fossilized bacteria indicative of the former presence of feathers. We confirmed the presence of fossilized bacteria in Confuciusornis and Caudiptertyx (Aves) and Sinornithosaurus (cf. Dromaeosauridae). Alternately, the preserved integument of Beipiaosaurus, Sinosauropteryx (dinosaurs) and Jeholopterus (pterosaur) lacked the presence of bacteria and were similar to preserved soft tissue in the orbit of Sinosauropteryx. Conventional wisdom notwithstanding, we conclude that the filamentous integument preserved in these latter three taxa is unlikely to have been feathers, or antecedents to them.