The blood vessels found in T. rex bones rewrite what we know of dinosaurs

The researchers discovered blood vessels from Scotty, the largest Fossil of T. Rex. High power x -rays have revealed mineralized tissues that deepen our understanding of the biology of dinosaurs.

Although a large part of modern paleontology is devoted to the search for organic traces in fossils, no dinosaur sample DNA has already been recovered.

Most of what scientists know dinosaurs come from their bones and their teeth preserved in the rock record. Although these hard tissues are invaluable, they only offer limited information on the biology and appearance of the animals themselves.

On the other hand, soft tissues are extremely rare in fossils but can provide a much richer and more detailed image of ancient life. The examples include preserved muscles, ligaments, pigments or even skin impressions such as ladders or feathers, which reveal information on the way dinosaurs lived and what they looked like.

Another interesting soft fabric that can be found in the bones is the blood vessels. My research team and I discovered blood vessels preserved in a Tyrannosaurus rex fossil, and our results have recently been published in Scientific relationships.

As a student in undergraduate physics at the University of Regina, I joined a research team using particle accelerators to study fossils. There, I first discovered blood vessels in a bone of a T. Rex Using advanced 3D models. It’s been almost six years since that time; I now work on my doctorate where I use my history in physics to advance analysis techniques in fossil research.

An extraordinary specimen

The preserved ships came from an exceptional T. Rex Specimen nicknamed Scotty. Installed at the Royal Saskatchewan Museum in Canada, Scotty is the biggest T. Rex Never discovered and remains one of the most complete skeletons of the species.

The evidence of the bones suggest that Scotty lived a difficult life 66 million years ago, with many injuries that were able to result from one fight with another dinosaur or the disease. A particular coast showed a large fracture which had partially healed before the death of the animal.

In general, after the bones undergo a traumatic event as a fracture, there is a huge increase in the activity of blood vessels in the area affected within the framework of the healing process. We believe that this was found in the Scotty coast: a large network of mineralized ships that we were able to examine using reconstructed 3D models.

Review research in paleontology

During the analysis of fossil bones, there are two main challenges. The first is how to examine the interior of the bones without damaging the fossil. And second, the bones are very large and can be fairly dense due to the fossilization process, where minerals replace and fill the original organic matter.

At the beginning, we thought that we could perform a calculated topography (CT) of the OS, similar to what is used for medical purposes, which allows bone imagery without damaging them. Although this solves the first problem, the second problem means that a conventional medical CT machine is not powerful enough to penetrate the dense bone.

For our examination, we used Synchrotron light, high intensity special X -rays. These are produced in certain particle accelerator laboratories and allow us to easily study microstructures such as blood vessels in the bone.

Synchrotron X -rays can also be useful for chemical analysis. We found that the ships were kept like mineralized iron ruffles, a common shape of fossilization, but in two distinct layers. This superposition is due to the complicated environmental history which led to the exceptional preservation observed in the Côte de Scotty.

Written in blood vessels

By analyzing the blood vessels produced by an incompletely healed fracture, we can know how T. Rex Ford, helping speculation on how Scotty was able to survive after suffering from injuries. This could lead to evolutionary information by comparing the structures of ships observed in Scotty to other species of dinosaurs, as well as modern parents with dinosaurs such as birds.

The results can also help flee fossil exploration by guiding scientists to target bones that show signs of injury or disease, potentially increasing the chances of discovering more vessels or other types of preserved soft tissue.

With interdisciplinary research and new applications of advanced technologies, there is so much potential to recreate the past life of dinosaurs like never before.

Reference: “In situ analysis of vascular structures in the fracture of the Côte de Tyrannosaurus Rex” by Jérit L. Mitchell, Mauricio Barbi, Ryan C. McKellar, Monica Cliveti and Ian M. Coulson, July 4, 2025, Scientific relationships.
DOI: 10.1038 / S41598-025-06981-Z

Adapted from an article initially published in the conversation.

Jerit Leo Mitchell receives funding from Mitacs Accelerate and Sylvia Fedoruk Center for Nuclear Innovation.

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