Chinese, American and Canadian scientists on Thursday announced their discovery of the fossil of a dinosaur that suffered tooth disease and lost a tooth.
It is a key advance in scientists' understanding of how dental issues develop in dinosaurs, with an article in the latest volume of the Chinese Science Bulletin describing the 190 million-year-old fossil as "the first confirmed example of such dental pathology in a dinosaur."
The article was coauthored by Prof. Zhang Jianping and doctorate candidate Xing Lida of the School of Earth Sciences and Resources at Beijing's China University of Geosciences; Prof. Bruce Rothschild of the University of Kansas in the United States; and Dr. Phil Bell of the Pipestone Creek Dinosaur Initiative in Canada, among other authors.
Pathological or traumatic loss of teeth often results in the resorption and remodeling of the affected alveoli in mammals. However, instances of alveolar remodeling in reptiles are rare, the article says.
Paleopathology is the study of disease and other abnormalities in the fossil record, it explains, adding that paleopathological investigations can "reveal unique insights into the behavior, biology and development of extinct animals."
The fossil was discovered in in 2007, when the Lufeng Dinosaurian Museum recovered an incomplete skull and several postcranial fragments of a new specimen of Sinosaurus from the Lufeng Basin in southwest China's Yunnan Province.
Paleontologists found that the dinosaur's skull was missing a tooth, but its alveolus was completely closed, which was rare and possibly a pathological change. They conducted X-rays and CT scans on the specimen.
The total closure of the dinosaur's alveolus and remodeling of the alveolar space indicate the animal survived for a lengthy period of time following the loss of the tooth, the article says.
"This finding adds to the known range of dental pathologies found in theropods and contributes to mounting evidence suggesting theropods were highly resilient to a broad spectrum of traumas and diseases," it adds.