Unprecedented preservation of soft tissues and organic matter in fossils characterized by synchrotron radiation techniques

Abstract

Fossilization is a rare process. Many orders of magnitude rarer is fossilization of “lifelike” soft tissues or original organic molecules, as compared to mineralized components such as bones and teeth. To probe for these extraordinary structures, a useful tool that can be employed is synchrotron radiation — extremely intense photons that can analyze complex heterogeneous samples with unmatched resolution, signal-to-noise ratios, and acquisition times. Synchrotron radiation has revolutionized palaeontology research, challenging conventional limits of taphonomy, the study of decay and fossilization, and providing abundant information about ancient life. In this thesis I will discuss the application of synchrotron radiation techniques using the Canadian Light Source in search of exceptional preservation in fossils. This will include techniques such as computed tomography, X-ray fluorescence, X-ray absorption spectroscopy, infrared spectroscopy, as well as conventional techniques such as scanning electron microscopy. The highlights of the research include: finding remnants of preserved organic chitin in a beetle from Baltic amber, which is the oldest and most well preserved for its age chitin ever reported in a fossil beetle; and finding angiogenic blood vessels preserved in a fractured rib bone from Tyrannosaurus rex, where combining high resolution three-dimensional modeling and chemical analysis of dinosaur blood vessels has not been described before in literature. I show how the use of several in situ, minimally destructive techniques on a single sample can be compared to provide a thorough analysis of fossils and confirm the presence of endogenous molecules and soft tissue structures.