ULTRASTRUCTURAL ANALYSIS OF PUTATIVE OF DINOSAUR INTEGUMENT

The question of the origin and antiquity of feathers has been intractable since the accurate identification of integumentary tissues in fossils can be problematic. However, the presence of lithified bacteria that had once been associated with decomposing keratin may allow for a more empirical means to identify fossilized feathers than has generally be employed. Putative integument from dinosaurs, birds, and pterosaur fossils from Cretaceous deposits of China were analyzed for lithified bacterial signatures. We have been able to confirm that the presence of lithified bacteria in the putative integument associated with the avian specimens; this indicates that this tissue was originally keratinous. However, this was not the case in all of the analyzed specimens; in these cases, the putative tissue is unlikely to have been integumentary.