AN INVESTIGATION OF THE PROCESSES INVOLVED IN AVIAN THAPHONOMY

Recently discovered specimens of small theropod dinosaurs from China have been found to exhibit various integumentary structures that have come to be known as "dino-fuzz." Most researchers have interpreted these structures as the remains of body feathers. As part of an investigation into the nature of dino-fuzz and whether or not it is homologous with modern avian feathers, we are studying the processes by which birds may become fossilized. We have simulated the manner by which birds and bird feathers become fossilized by using modern bird carcasses and various substrates and conditions. By closely observing post-mortem decomposition and simulating the process of diagenesis and taphonomy, we have obtained valuable information and insights into the way small, feather-covered dinosaurs and birds may have became fossilized in the past and what environmental conditions may be necessary for their fossilization. Our findings have shown that although birds do float in water, they will eventually sink after a period of decomposition and become embedded the substrate beneath them. In contrast, birds that fall into a moist, muddy, clay substrate directly tend to become fixed immediately and do not float after subsequent inundation with water. It seems likely that this is the primary mechanism by which birds (and by correlation small feathered dinosaurs) are likely to become buried in sediment. Finally, we have analyzed the types of feathers that tend to remain attached to the carcass and how they and other feathers are distributed around the carcass during decomposition. This analysis is currently shedding light on the true nature of dino-fuzz.