First case of bone cancer discovered in dinosaurs, scientists claim

The Centrosaurus apertus, a horned dinosaur that lived 76 to 77 million years ago in present day Canada. - Mark Stevenson/Stocktrek Images
The Centrosaurus apertus, a horned dinosaur that lived 76 to 77 million years ago in present day Canada. - Mark Stevenson/Stocktrek Images

Dinosaurs suffered from cancer, new research has revealed, indicating the disease is fundamental to the animal kingdom.

Scientists claim to have discovered the first case of an aggressive malignant bone cancer - known as an osteosarcoma - in a plant-eating dinosaur.

The findings have been published in the medical journal The Lancet Oncology.

The cancerous bone was the fibula - lower leg bone - from Centrosaurus apertus, a horned dinosaur that lived 76 to 77 million years ago in present day Canada.

Originally discovered in Dinosaur Provincial Park in Alberta in 1989, the badly malformed fossil was originally thought to be a healing fracture.

Noting the unusual properties of the bone on a trip to the Royal Tyrrell Museum in 2017, Dr David Evans, of the Royal Ontario Museum (ROM), Professor Mark Crowther and Snezana Popovic, an osteopathologist, both of McMaster University, decided to investigate.

They assembled a team of specialists and approached the diagnosis similarly to how it would be carried out in humans.

Prof Crowther said: "Diagnosis of aggressive cancer like this in dinosaurs has been elusive and requires medical expertise and multiple levels of analysis to properly identify.

"Here, we show the unmistakable signature of advanced bone cancer in a 76-million-year-old horned dinosaur - the first of its kind. It's very exciting."

The main tumour mass is at the top of the bone, and can be seen on the 3D reconstruction in yellow; red gray is the normal bone and red denotes the medullary cavity.  - Reprinted from The Lancet Oncology, Seper Ekhtiari, Kentaro Chiba, Snezana Popovic, Rhianne Crowther, Gregory Wohl, Andy Kin On Wong, Darren H Tanke, Danielle M Dufault, Olivia D Geen, Naveen Parasu, Mark A Crowther, *David C Evans, History of Medicine First case of osteosarcoma in a dinosaur: a multimodal diagnosis, Copyright (2020), with permission from Elsevier.

After examining, documenting, and casting the bone, the team performed high-resolution computed tomography (CT) scans. Powerful three-dimensional CT reconstruction tools visualised the progression of the cancer through the bone.

To confirm the diagnosis, the team then compared the fossil to a normal fibula from a dinosaur of the same species, as well as to a human fibula with a confirmed case of osteosarcoma.

Osteosarcoma is a bone cancer that usually occurs in the second or third decade of life.

The fossil specimen is from an adult dinosaur with an advanced stage of cancer. Yet it was found in a massive “bonebed”, suggesting it died as part of a large herd of Centrosaurus struck down by a flood.

Dr Evans said the bone shows an “aggressive cancer”: “(It) would have had crippling effects on the individual and made it very vulnerable to the formidable tyrannosaur predators of the time”.

He added the fact it lived in a large protective herd may have helped its survival.

Dr Evans said that establishing links between human disease and the diseases of the past will help scientists to gain a better understanding of their evolution and genetics.