In 2004, Mary Schweitzer discovered soft, stretchy tissue in a T. rex fossil, sparking scientists’ interest in understanding how biological tissues and cells could survive in ancient organisms. One of the most popular hypotheses involves a process called crosslinking, which fixes tissues of ancient organisms like dinosaurs, similar to the way formaldehyde is used to preserve tissues. Fixatives like formaldehyde make the tissues less digestible to bacteria, preventing their degradation.
Landon Anderson, a doctoral candidate at NC State, led a study in Earth Science Reviews that explored the chemical pathways that lead to crosslinking. The study shows that at least two popular hypotheses, including one from Schweitzer and her colleagues on oxidation driven by certain dissolved metals and another from paleontologist Jasmina Wiemann and her colleagues on carbonyl groups of fats and carbohydrates, share a chemical pathway and overlap significantly. They both lead to the formation of crosslinked biomolecules that stabilize the overall tissue.
Anderson believes that understanding the general chemical theory behind the processes involved is an essential first step in demystifying the preservation of soft tissue in deep time. He suggests that the predominant preservation pathways could change under different environmental conditions, and more research is needed to answer many questions regarding soft tissue preservation in ancient organisms. Nonetheless, Anderson’s study provides a sound theoretical basis for understanding why crosslinking occurs and why preservation of various original cellular tissues, including vertebrates and other organisms trapped within amber, carbonized traces of ancient feathers and skin, and even dinosaur mummies, is plausible.
Source: North Carolina State University