A new study has discovered that nearly 69 million years ago, a duck-billed dinosaur dwarf roamed on Earth with a facial tumor, specifically present on the slower jaw. According to the researchers, the unusual growth likely did not cause any pain.

The presence of a similar tumor is common in some other forms of modern reptiles and mammals, including humans. However, this is the first time that researchers have discovered the presence of a tumor on fossils of a dwarf dinosaur.

The early duck-billed dinosaur that is being referred to is "Telmatosaurus transsylvanicus," also known as a hadrosaur. This discovery is first of its own kind to be described in a fossil record and the first one to be documented in details for a dwarf dinosaur.

According to the researchers, the discovery of a tumor in fossils of dwarf dinosaur indicates that they were more prone to tumors that other species of dinosaurs. Researchers further said that Telmatosaurs are closely related to the duck-billed dinosaur family tree and the presence of such a deformity early in their evolution holds a significant importance.

The fossils of Telmatosaurus were recovered nearly a decade ago by the researchers from the "Valley of the Dinosaurs" in Romania. The site is honored as a World Heritage by the United Nations Educational, Scientific and Cultural Organization (UNESCO).

The fossil appeared deformed at the time when it was discovered. However, the researchers are still not sure about the cause of the deformity. The research team used computer tomography later to "peek unintrusively inside the peculiar Telmatosaurus jawbone" and discovered that the dinosaur had ameloblastoma, which a noncancerous, benign growth that affects the jaw. The researchers said that humans do not feel any sought of pain from ameloblastoma and it is likely that dinosaurs did not feel it either.