Palaeontologists have dusted off a fossilized dinosaur tail that contains clear evidence of a nasty disease. Remarkably, some 66 million years later, this rare condition can still be found in humans today.
The fossilized tail vertebrae once belonged to a young hadrosaur, duck-billed herbivores that lived in large herds across the planet between 80 and 66 million years ago. Although this family of dinosaurs included a diverse range of species, they were generally huge beasts, measuring over 10 meters (32.8 feet) in length and weighing several tons.
After the fossil was unearthed from a prairie in southern Alberta, Canada, a team of researchers at Tel Aviv University (TAU) in Israel noticed that two of the vertebrae segments (image below) contained large cavities. A closer inspection showed that the unusual cavities were very similar to the lesions seen in people suffering from the disease Langerhans cell histiocytosis (LCH).
The study, published in the journal Scientific Reports, marks the first time such a disease has been identified in a dinosaur.
"We scanned the dinosaur vertebrae and created a computerized 3D reconstruction of the tumor and the blood vessels that fed it. The micro and macro analyses confirmed that it was, in fact, LCH,” lead author Dr Hila May, of the Department of Anatomy and Anthropology at TAU's Sackler Faculty of Medicine, said in a statement.
LCH is a form of rare disease (sometimes referred to as cancer) caused by a mutation that leads to Langerhans cells, a type of immune cell that fights infections, growing and multiplying uncontrollably. This can cause the cells to build up, resulting in deep tissue damage or lesions in the bone. As you can imagine, it can be an extremely painful disease. It’s most often found in young children and most patients manage to survive.
It’s typically associated with humans, but LCH has been documented in a few other animals, such as tigers and a tree shrew. However, as mentioned, it’s never been seen in an extinct animal.
Diseases in dinosaurs are generally hard to diagnose, although it’s not totally unheard of. In 2016, scientists found the first case of septic arthritis in a hadrosaur fossil, an inflammation of the joints caused by a bacterial infection within bone cartilage. Equally, it’s well-established that dinosaurs were affected by cancer too. Using new tools and techniques, it’s hoped we can diagnose more dinosaur diseases, which could also shed some light on human diseases and their origins.
"These kinds of studies... make an important and interesting contribution to evolutionary medicine, a relatively new field of research that investigates the development and behavior of diseases over time," noted Professor Israel Hershkovitz of TAU's Department of Anatomy and Anthropology and Dan David Center for Human Evolution and Biohistory Research.
"We are trying to understand why certain diseases survive evolution with an eye to deciphering what causes them in order to develop new and effective ways of treating them."