London: The first-ever record of a tumourous facial swelling found in a fossil has been discovered in the jaw of an estimated 69 million-year-old dwarf dinosaur, say researchers. The fossil was discovered in the 'Valley of the Dinosaurs' in the Dinosaurs Geopark in Transylvania, western Romania. The non-cancerous facial tumour found on Telmatosaurus -- a type of primitive duck-billed dinosaur and also known as a hadrosaur -- had been previously seen in humans, mammals and some modern reptiles, but never before encountered in fossil animals. "This discovery is the first ever described in the fossil record and the first to be thoroughly documented in a dwarf dinosaur,” said Kate Acheson, doctoral student at the University of Southampton in Britain. “Telmatosaurus 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 the duck-billed dinosaurs were more prone to tumours than other dinosaurs," Acheson added. The study was published in the journal Scientific Reports. Scans taken of the Telmatosaurus fossil suggested that the dinosaur suffered from a condition known as 'ameloblastoma' -- a tumourous, non-cancerous growth known to afflict the jaws of humans and other mammals and some modern reptiles, too. It is unlikely that the tumour caused the dinosaur any serious pain during its early stages of development, just as in humans with the same condition, but this particular dinosaur died before it reached adulthood, the researchers said, though they could not ascertain the cause of its death. "The tumour in this dinosaur had not developed to its full extent at the moment it died, but it could have indirectly contributed to its early demise," Zoltan Csiki-Sava from the University of Bucharest in Romania noted.