A team of paleontologists from the University of Zurich has identified chronic instances of osteomyelitis (bone tissue infection) in Plateosaurus trossingensis, one of the well-known dinosaurs from the late Triassic period in Europe.
Diagram of Plateosaurus trossingensis skeletons featured in the Theoprati exhibition at the Museum of Natural History, University of Zurich. Image credits: Dupuy et al., doi: 10.1186/s13358-025-00368-3.
Plateosaurus trossingensis inhabited Europe around 220 million years ago during the late Triassic epoch.
These ancient creatures were approximately 8 m (26 feet) long and primarily walked on their hind legs.
In a recent study, paleontologist Jordan Bestwick and colleagues analyzed the skeleton of Plateosaurus trossingensis from the Klettgau Layer in Switzerland.
They discovered significant osteomyelitis in the dinosaur’s upper arm and right shoulder.
“Osteomyelitis affects various living animals, including humans, birds, and reptiles,” noted Dr. Bestwick.
“The condition has been documented in several dinosaur groups, including sauropods, leading us to assess and compare numerous specimens, including Plateosaurus.
“The impacted bones in the shoulders and upper arms displayed notably rough internal and external textures, altered shapes, and even fusion, which are broad indicators of osteomyelitis.”
Researchers find their discoveries particularly intriguing since this case represents the oldest recorded instance of osteomyelitis in dinosaurs, dating back to about 220 million years ago, and the extent of the infection was unusually large.
“Earlier studies highlighted localized infections, such as in toe bones or adjacent vertebrae,” Dr. Bestwick explained.
“It’s exceptionally rare to observe infections in a shoulder and the entirety of an upper arm.”
“While the initial cause of the infection remains unknown, it likely plagued the animal for a prolonged period, potentially rendering its right arm nonfunctional.”
These findings are detailed in a paper published in the Swiss Journal of Palaeontology.
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sfj dupuis et al. 2025. Osteology and histology of a Plateosaurus trossingensis (Dinosaur: Sauropodomorpha) from the Upper Triassic in Switzerland with advanced chronic pathology. Swiss J Palaeontol 144, 27; doi:10.1186/s13358-025-00368-3
Source: www.sci.news