Soft Tissue in Tyrannosaurus Femur (2005)

Mary Schweitzer's 2005 discovery of flexible blood vessels and protein fragments inside a 68-million-year-old T. rex femur in Montana challenges the assumption that organic material cannot survive fossilization. This find sparked ongoing debates about preservation mechanisms, with evidence from mass spectrometry revealing collagen sequences. It is 50% older than the previous oldest soft tissue find, outperforming #7 Velociraptor and Protoceratops Locked in Combat in biochemical significance. The femur contained seven distinct protein types, providing data that reshapes paleontological methods.