An international team of scientists discovered the first-ever evidence of tumor growth in a fossil from a dinosaur unearthed in the Valley of the Dinosaurs at the Haţeg County Dinosaurs Geopark in Transylvania, western Romania. Analysis suggests that the duck-billed hadrosaur had ameloblastoma, a benign, non-cancerous growth that also affects the jaws of humans, some mammals and several reptiles.

As stated by the study published on July 5 in the journal Scientific Reports, the tumor was found in the jaw of a primitive hadrosaur called Telmatosaurus transsylvanicus. This dwarf dinosaur is estimated to be between 69 to 67 million years old.

“This discovery is the first-ever described in the fossil record and the first to be thoroughly documented in a dwarf dinosaur,” says University of Southampton researcher and student Kate Acheson. “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.”


Telmatosaurus transsylvanicus. Credit: University of Southampton

The research team believes that the tumor did not cause any pain. The tumor did not reach its full development because the dinosaur died before it reached adulthood. They speculate that the tumor indirectly contributed to the dinosaur’s premature death.

However,  Zoltán Csiki-Sava of the University of Bucharest says that they do not know what caused the tumor growth. They are also unsure of what caused the dinosaur’s demise since the remains of two lower jaws is insufficient to reveal what happened.

They also theorize that the dinosaur was probably attacked  by a predator. Csiki-Sava explains that modern animals tend to attack a member of the herd that looks different or more disabled than the others.

Although the researchers expected to find diseases in the dinosaur fossils, they did not expect to find a disease that also affects modern animals. Their study involved the use of Micro-CT scanning to view the Telmatosaurus jawbone.

The international team also included researchers from Johns Hopkins University and Northeast Ohio Medical University, both from the US, as well as Bolyai University in Romania and University of Southampton in the UK.