Photo: Two Balaur bondoc predators pick a young duck-billed dinosaur out of the herd while the giant pterosaur soars overheard. Credit: Mihai Dumbrav During its lifetime about 69 million years ago, a duck-billed dinosaur dwarf walked around with a tumor on its lower jaw, though the unusual growth likely didn't cause any pain, a new study finds.
The same type of noncancerous facial tumor is also found in some modern reptiles and mammals, including humans. But this is the first time researchers have found it in a fossil animal, in this case on Telmatosaurus transsylvanicus, an early duck-billed dinosaur, also known as a hadrosaur, the researchers said. [Photos: Duck-Billed Dinos Found in Alaska]
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"This discovery is the first ever described in the fossil record and the first to be thoroughly documented in a dwarf dinosaur," one of the study's co-authors, Kate Acheson, a doctoral student of geology at the University of Southampton in England, said in a statement. "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 tumors than other dinosaurs."
Researchers found the fossils in western Romania in the "Valley of the Dinosaurs," which is part of a World Heritage site honored by the United Nations Educational, Scientific and Cultural Organization (UNESCO).
"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," study co-author Zoltán Csiki-Sava, a paleontologist at the University of Bucharest in Romania, said in the statement.