Scientists have discovered the first record of a fossil facial tumour in the jaw of a 69 million-year-old dwarf duck-billed dinosaur.

An international group of researchers, including Kate Acheson from the University of Southampton in the U.K., have documented a type of non-cancerous facial tumour, which is found in humans, mammals and some modern reptiles, but never before encountered in fossils.

“This discovery is the first-ever described in the fossil record and the first to be thoroughly documented in a dwarf dinosaur,” said Ms. Acheson.

“ Telmatosaurus transsylvanicus is known to be close to the root of the duck-billed dinosaur family tree, and the presence of such a deformity early in their evolution provides us with further evidence that duck-billed dinosaurs were more prone to tumours than other dinosaurs,” she said.

The hadrosaur fossil, estimated to be approximately 69 million years old, was discovered in the ‘Valley of the Dinosaurs’ in Transylvania, western Romania, researchers said.

“It was obvious that the fossil was deformed when it was found more than a decade ago but what caused the outgrowth remained unclear until now,” said Zoltan Csiki-Sava from University of Bucharest in Romania.

Researchers used micro-CT scanning facilities to study the peculiar Telmatosaurus jawbone.

The scans suggested that the dinosaur suffered from a condition known as an ‘ameloblastoma’, a benign, non-cancerous growth known to afflict the jaws of humans and other mammals, and some modern reptiles too, researchers said.

“The discovery of an ameloblastoma in a duck-billed dinosaur documents that we have more in common with dinosaurs than previously realised,” said Bruce Rothschild from Northeast Ohio Medical University in the U.S. The findings were published in the journal Scientific Reports . — PTI