Osteosarcoma is an aggressive bone cancer that occurs in humans, mostly children and young adults. It also afflicted a horned dinosaur 76 million years ago.
A study led by researchers at McMaster University and the Royal Ontario Museum in Canada has resulted in a surprising diagnosis of osteosarcoma in the fibula of a Centrosaurus apertus, a dinosaur that resembles the more familiar triceratops.
"No malignant cancers -- tumors that can spread throughout the body and have severe health implications -- have ever been documented in dinosaurs previously," McMaster University said in a release on Monday. The team published its findings in The Lancet Oncology journal this month.
Scientists originally thought the leg bone's odd shape came from a healed break, but a much closer look revealed the truth.
"After carefully examining, documenting and casting the bone, the team performed high-resolution computed tomography (CT) scans. They then thin-sectioned the fossil bone and examined it under a microscope to assess it at the bone-cellular level," McMaster said.
The researchers also compared the bone with a known case of osteosarcoma in a human and with a normal Centrosaurus apertus leg bone. Though the dinosaur's cancer was advanced, it appeared to have died in a flood rather than from the illness.
"The fact that this plant-eating dinosaur lived in a large, protective herd may have allowed it to survive longer than it normally would have with such a devastating disease," said paleontologist David Evans of the Royal Ontario Museum.
"Establishing links between human disease and the diseases of the past will help scientists to gain a better understanding of the evolution and genetics of various diseases," said McMaster University.
The dinosaur's diagnosis has created a thread across time, an unsettling connection between today and an ancient world.