A University of Regina research team made some key discoveries about how dinosaurs may have healed from injuries when they examined the preserved blood vessel structures inside a rib bone from Scotty, a famous Tyrannosaurus rex (Cretaceous period) unearthed in Saskatchewan in the 1990s.
Scotty is considered the heaviest and one of the longest-lived T. rex specimens ever discovered. The fossil is catalogued as RSM P2523.8.
Tyrannosaurus was one of the most fearsome animals of all time. Its powerful jaws had 60 teeth, each one up to 20cm (8 inches) long and its bite was around 3 times as powerful than that of a lion.
Jerit L. Mitchell, a PhD student in the Department of Physics at the University of Regina, is the study’s lead author, who joined the research project in 2019 when Scotty’s rib was scanned at the Canadian Light Source (CLS) for the first time. Mitchell was finishing his undergraduate honours thesis research when he discovered the vessel structures.
“I remember showing my supervisors, Dr. Barbi and Dr. McKellar, a strange structure inside a scan of the rib that I originally didn’t give much thought to. They were quick to point out that what I discovered could possibly be preserved blood vessels, which has since led to a much more expansive research project,” says Mitchell in a research note.
The synchrotron X-rays produced by the CLS at the University of Saskatchewan enabled the researchers to create a detailed 3D model of both the T. rex bone and the soft tissue structures that reside inside without damaging the 66-million-year-old fossil.
Then, using chemical analysis, the researchers determined what elements and molecules make up the vessel structures, allowing them to hypothesize how the structures were preserved over millions of years.
The X-rays of Scotty’s rib showed a healed fracture, possibly due to a fight with another dinosaur. This discovery could provide important, evolutionary information to researchers, such as the healing potential of a T. rex.
Preserved blood vessel structures, such those isolated from Scotty’s rib bone, appear linked to areas where the bone was healing. This is because during the healing process, those areas had increased blood flow to them.
In addition, the work provides a new way to compare how injuries healed in extinct animals, like dinosaurs, with living species, such as birds and reptiles, which helps us better understand the biology of the past, and also how life on Earth has evolved over millions of years.
This multidisciplinary study involved researchers from the University of Regina’s departments of physics, biology, and earth sciences, along with the Royal Saskatchewan Museum (RSM).
Fossils like those from Scotty are more than museum exhibits, continue to advance science and the use of advanced technologies help to keep the fossils intact for future generations.
The research appears in the journal Science Advances, titled: “In situ analysis of vascular structures in fractured Tyrannosaurus rex rib”.
