The partial fibula—a bone from the lower leg—belonged to a horned, plant-eating Centrosaurus that lived roughly 76 million years ago in what is now Dinosaur Park in southern Alberta in Canada.
Paleontologists initially thought the bone’s strange shape was due to a fracture that hadn’t healed cleanly. But a new study, published today in The Lancet Oncology, compares the internal structure of the fossil (above) with a bone tumor from a human patient to seek a diagnosis. The conclusion: The dinosaur suffered from osteosarcoma, a cancer that, in humans, primarily attacks teens and young adults. The disease causes tumors of immature bone tissue, frequently in the long bones of the leg.
This isn’t the first time cancer has been found in fossil remains. Scientists have identified benign tumors in Tyrannosaurus rex fossils and arthritis in duck-billed hadrosaurs, as well as an osteosarcoma in a 240-million-year-old turtle. But the researchers say their study is the first to confirm a dinosaur cancer diagnosis at the cellular level.
Continue reading @ Science Magazine.