Applications of Synchrotron Radiation Techniques To The Study Of Taphonomic Alterations and Preservation in Fossils

Abstract

Fossils have traditionally been seen as sedimentary rocks that preserve little of the original composition of animals, except for their shapes, and perhaps some original material from recalcitant mineralized structures, such as bones, and teeth. However, recent studies have shown that not the case. Researchers have identified preserved organic molecules, such as collagen and melanosomes, as well as mineralized soft tissues, including feathers, muscle tissue and skin, tens of millions of years after the animal's death. These results have improved our understanding of extinct species, and have been obtained using a variety of characterization techniques, including the synchrotron-based approaches that are the focus of the research presented in this thesis. The main goal of the research discussed in this thesis was the application of synchrotron radiation techniques (X-ray uorescence and X-ray absorption spectroscopy, in particular) in order to determine the taphonomic alterations that fossils experience, and examine how different materials are preserved. In this thesis, I discuss the results of the chemical characterization on the remains of the Tyrannosaurus rex known as \Scotty", turtle shells, and a rare specimen of fossilized hadrosaur skin. I also examine the applicability of X-ray

uorescence to determine the composition and elemental distribution of insect inclusions in amber. The results presented herein offer possible explanations on how some of these specimens were preserved and the extent of the chemical alterations they underwent during their taphonomic history. Beyond the specific results for each specimen, the overall research presented in this thesis shows that synchrotron radiation techniques have great potential to advance palaeontological research, as it becomes necessary to evaluate the chemistry of specimens in high resolution. These characterization techniques were able to con rm that more original material is preserved after fossilization than would have been believed possibly even a decade ago.