A team of researchers announced Tuesday that they have found the first record of a tumourous facial swelling in a fossil. It was discovered in the jaw of the dwarf dinosaur, the Telmatosaurus transsylvanicus, a type of duck-billed creature better known as a hadrosaur.
The team documented a type of non-cancerous facial tumor in the extinct creature, the same kind found in humans, mammals, and some modern reptiles. It is the first time such discovery is encountered in fossil animals, according to the study published in the journal Nature.
“This discovery is the first ever described in the fossil record and the first to be thoroughly documented in a dwarf dinosaur,” Kate Acheson, a Ph.D. student at the University of Southampton, commented in a press release from the institution. “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.”
The fossil is estimated to be about 67 million years old and was discovered in the “Valley of the Dinosaurs” in the Haţeg County Dinosaurs Geopark in Transylvania, western Romania. The site is part of a World Heritage place honored by the United Nations Educational, Scientific, and Cultural Organization (UNESCO).
When the remains were found over a decade ago, it was noticeable that the fossil was deformed, but what exactly caused the outgrowth was unclear until now, said Dr Zoltán Csiki-Sava of the University of Bucharest, Romania, who led the field trip which uncovered the fossil.
To investigate the unknown factors that could lead to the deformation of the animal, the team was invited by SCANCO Medical AG in Switzerland to use their Micro-CT scanning facilities and further study the fossil, Csiki-Sava added. The investigations suggested that the dinosaur suffered from a condition known as an ‘ameloblastoma.’
According to Dr Bruce Rothschild, from the Northeast Ohio Medical University, an expert in palaeopathology and who studied the scans, the discovery of an ameloblastoma in a duck-billed dinosaur documents that the human kind and even modern animals have more in common with dinosaurs than previously thought due to they have the same neoplasias.
It is unlikely that the tumor caused the dinosaur any serious pain during its early stages of development like it is expected in humans with the same condition, but the team can tell from the size of the bones and that the animal dies before it reached adulthood.
As for the cause of death, it would remain unknown due to what they team have found from the dwarf dinosaur were only the two lower jaws. The team would need more information from other parts of the body to be positive about the cause of death.
Although the hope to find the complete specimen is almost nonexistent due to the fossil was preserved near the channel of an ancient river. According to Acheson, in a setting of such kind, it is extremely rare to find the complete remains and so it is almost impossible to ever determine the specific cause of death.
However, the team remained wondering if the tumor may have contributed to the animal’s death. A theory is that perhaps the tumor made the dinosaur look different or even slightly disabled by the disease, which could have made it a clear target for predators looking for susceptible prey, commented Csiki-Sava.
“We know from modern examples that predators often attack a member of the herd that looks a little different or is even slightly disabled by a disease. The tumor 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,” added Csiki-Sava.
Not the first tumor overall
Even though the recent discovery accounted as the first finding of its kind, fossils have shown tumors on dinosaurs before. Researchers previously found two tumors on an individual Titanosaur, a long-necked, long-tailed herbivorous giant, and on the duck-billed dinosaurs Brachylophosaurus, Gilmoreosaurus, Bactrosaurus, and Edmontosaurus, as well as the carnivorous, Jurassic-age Dilophosaurus wetherilli, as reported by LiveScience.
In the dinosaur with two types of tumors, those were found on the same bone, the vertebra. The 7-inch-long fossilized vertebra was discovered in Brazil’s southern São Paulo state, and it belonged to a species in the Titanosauridae family, the most common one within the Cretaceous dinosaur family of South America.
The tumors were benign and due to their size it is possible that the dinosaur never noticed, commented Fernando Barbosa, a doctoral student of geology at the Federal University of Rio de Janeiro in Brazil.
“We were very lucky finding this because we didn’t have any evidence of the hemangioma,” Barbosa told LiveScience in an email. “It was diagnosed by the CT scan, which was only possible because we were investigating the radiological appearance of the osteoma.”