Dinosaurs got tumours, too

Cancer was common in some dinosaurs, according to study of their bones.

Radiologist Dr. Bruce Rothschild of the Northeastern Ohio Universities College of Medicine in Rootstown and his colleagues used a portable X-ray machine to scan dinosaur bones across North America.

Scientists have found signs of tumours in dinosaurs before, but the researcher say this was the first large-scale bone survey.

The researchers looked at 10,000 dinosaur vertebrae from more than 700 museum specimens, including ones from the Royal Tyrrell Museum, Royal Ontario Museum and Canadian Museum of Nature.

Although they studied Stegosaurus, Triceratops and Tyrannosaurus specimens, only the hadrosaurs or "duck-billed dinosaurs" showed tumours.

The team first clued into the dino tumours when they received calls from colleagues who thought they had spotted tumours in dinosaur bones. They turned out to be correct.

Rothschild said the prehistoric tumours look like human ones.

The 3.5-metre Edmontosaurus seemed to be the most tumour-ridden. It was the only species with a malignant tumour, the researchers say. About three per cent of its bones had some kind of tumour.

Hemangiomas, benign tumours of the blood vessels, were the most common type of cancer in the hadrosaurs.

Studies of hadrosaur teeth and fossilized stomach contents show the dinosaurs ate cones from evergreen trees. Carcinogens in the cones may explain why they had tumours, Rothschild says.

Hadrosaurs also seem to have been more warm-blooded than other dinosaurs, which may explain their predisposition to tumours.

Rothschild worked with colleagues at the University of Kansas Museum of Natural History and the Royal Tyrrell Museum of Paleontology in Drumheller, Alta.

Their study appears in the Oct. 14 online issue of the journal Naturwissenschaften.