A broken bone triggers a remarkable healing process in the body. New blood vessels form, bringing in oxygen and nutrients to mend the damage. Recently, scientists discovered that this same process took place in a Tyrannosaurus rex rib from about 67 million years ago. Using sophisticated X-rays, they detected mineral patterns where blood once flowed.
The study focused on a fracture near the end of the T. rex rib. Evidence showed the bone began to heal before the dinosaur’s death, forming a callus—the bumpy tissue that develops during repairs. Inside that callus, researchers found structures resembling blood vessels, connecting their findings to modern medical knowledge about healing.
This research centers on a famous T. rex specimen named “Scotty,” kept at the Royal Saskatchewan Museum. Scotty is one of the most complete T. rex skeletons ever found. The research team, led by Jerit L. Mitchell, a PhD student at the University of Regina, scanned the rib at the Canadian Light Source, a facility known for its high-resolution imaging.
Mitchell recalls when he first noticed a peculiar structure in the rib scan back in 2019. Initially, he didn’t think much of it. However, his supervisors pointed out that it could be preserved blood vessels, sparking a more extensive research project.
The structures observed were localized around the fracture site, rather than throughout the rib, indicating they were related to healing. They were larger than the tiny canals typically found in bones. This aligns with findings in modern medicine: during the healing process, new blood vessels increase to supply the injured area.
The research team opted not to grind down the fossil, preserving it for future study. They used synchrotron micro-CT imaging to create three-dimensional images, discerning the fine tube structures within the callus. Their methods included utilizing X-ray fluorescence (XRF) to analyze elements and X-ray absorption near-edge structure (XANES) to identify chemical states.
Notably, the structures were rich in pyrite, often called fool’s gold. This material can stabilize organic structures during fossilization, helping preserve traces of soft tissues long after the original vessels have vanished.
Interestingly, these findings offer insight into how healing in dinosaurs might relate to modern-day animals. Just like today, T. rex experienced an increase in blood flow to the healing areas. This discovery could also help researchers understand how life on Earth has changed over millions of years.
The precise location and size of the observed structures support the idea that they were indeed linked to the healing process. They formed in response to the fracture, much like temporary vessels expand in contemporary animals.
This work highlights the potential of fossils to capture moments of intense biological activity. Injuries in ancient creatures can help us draw parallels with living species, improving our understanding of evolution and biology.
Through this study, researchers have shown that advanced non-destructive tools can unveil fragile features without harming valuable fossils, a significant step forward in paleontology.
Looking ahead, healed injuries in dinosaurs may be prime spots for further exploration. As techniques improve, scientists could compare healing processes across species, increase our knowledge of metabolism, and examine how burial environments influence preservation.
A single rib from Scotty paints a detailed picture: blood flowed to the wound, vessels expanded, bones knit together, and minerals captured the story left behind—an imprint from millions of years ago.
The full study was published in Scientific Reports.
