A new remarkable fossil dating back to the late Cretaceous period has revealed that dinosaurs could also suffer from facial tumors, just like many animals around the world, including humans, still do today. As if the dinosaurs didn’t already have enough to worry about with the prolonged volcanic eruptions in India changing the climate, the rise of opportunistic mammals, and the impending cataclysmic asteroid strike.
This unfortunate hadrosaur, a dwarf-sized duck-billed herbivore, died sometime around 69 to 67 million years ago, making it one of the last non-avian dinosaurs to have plodded the Earth. Unearthed in the Valley of the Dinosaurs in Romania, a dinosaurian fossil treasure trove, it was readily identified as a Telmatosaurus transsylvanicus (meaning “Transylvanian marsh lizard”) before its excavators noticed something peculiar about its jaw.
“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,” Zoltán Csiki-Sava, a paleontologist at the University of Bucharest, co-author of the study, and the field trip lead, said in a statement. “In order to investigate the outgrowth, our team was invited by SCANCO Medical AG in Switzerland to use their Micro-CT scanning facilities and to ‘peek’ un-intrusively inside the peculiar Telmatosaurus jawbone.”
The scans revealed that the 4-meter-long (13 feet) dinosaur suffered from an ameloblastoma, a commonly benign, non-cancerous tissue growth that is also found in the jaws of other reptiles and mammals today. This particular growth, which tends to form in the lower jaw, is considerably rare these days, although it’s not clear how common it was in dinosaurs back during the Cretaceous period.
Although not dangerous, its proliferation across the jaw can cause severe abnormalities if left untreated. In fact, they can grow to such a size that the nasal and oral airways can be blocked, which could eventually cause asphyxiation.
As the team note in their study in the journal Scientific Reports, it is unlikely that this particular hadrosaur suffered from any serious pain during the earlier stages of its development, but it does appear that it died just before reaching adulthood. As only the lower jaw bones are preserved, a cause of death cannot be ascertained, but the researchers openly wonder if the ameloblastoma contributed to its death in some way, perhaps through airway blockage.
Although this isn’t the first tumor growth found on a fossilized dinosaur – back in 2003, for example, the first dinosaur brain tumor was discovered attached to a Gorgosaurus, a type of tyrannosaur – it certainly gives credence to the idea that cancer hasn’t changed too much over the years, and that it’s an affliction that has affected a diverse range of organisms over geological time scales.
Images in text: Top - a 3D reconstruction of the swollen growth on the lower left jawbone. Dumbravă et al./Scientific Reports.
Bottom: An artist's reconstruction of the specimen's face, with the ameloblastoma appearing just on its left lower jaw. M. Dumbravă