Some of the more outstanding fossils from the Early Cretaceous Jehol Biota of NE China are the early birds and feathered dinosaurs. Any interpretation of the biology of the birds and dinosaurs from the Jehol Biota inherently depends on a full understanding of their taphonomy, which must be investigated. We explore the taphonomy of the Jehol birds and dinosaurs from different deposits. In particular, we determine the likelihood that volcaniclastic flows were responsible for the death transport and burial of these animals. Field observations and analysis of Psittacosaurus fossil matrices from the fossil-rich volcaniclastic deposits of the Lujiatun Unit reveals animals were not killed by a previously hypothesised single volcanic event and were instead buried within remobilised volcaniclastic material. Using semi-quantitative skeletal taphonomy metrics we test the hypothesis that all allochthonous components of the Jehol Biota were killed, transported and deposited in a lake by a pyroclastic density current. Analysis of the skeletal taphonomy of the early bird Confuciusornis and feathered microraptorine dinosaurs reveals that these animals were not transported in a pyroclastic or turbulent flow of any other kind. The decay process in the skin of birds and squamates is documented for the first time at an ultrastructural level. Results show that decay of skin progresses differently between individuals and within the same individual over short distances. From this, we develop a predictive model for the likelihood of the various components of the skin being available or unavailable for preservation in the fossil record at different points in the decay process. We also employ micro-computed tomography to image decayed bird skin and muscle. The advantages of imaging decay on non-biomineralized tissues using each method in isolation and as part of an integrated approach are then discussed.
|Date of Award||24 Jan 2017|
- The University of Bristol
|Supervisor||Stuart L Kearns (Supervisor), Patrick J Orr (Supervisor), Maria E Mcnamara (Supervisor) & Michael J Benton (Supervisor)|