Discovery of 220-Million-Year-Old Dinosaur Infection Reveals Paleopathology Insights

Researchers from the University of Zurich (UZH) and the Frick Dinosaur Museum have documented a remarkable paleopathological finding—the oldest known case of osteomyelitis in a dinosaur, dating back approximately 220 million years. This significant discovery centers around a Plateosaurus skeleton, unearthed in the Frick Valley of Switzerland, which exhibited severe bone infection that likely incapacitated its right arm. The findings were published in the Swiss Journal of Palaeontology on June 16, 2025.

The Plateosaurus, a nearly eight-meter-long herbivorous dinosaur, lived during the Late Triassic period in an area that resembled a dry playa, characterized by its susceptibility to flooding. The dinosaur's demise was likely due to becoming trapped in mud, a fate common to its species. However, this individual faced additional challenges due to a chronic bone infection exacerbated by its environmental circumstances.

Dr. Sina F. J. Dupuis, lead author and paleontologist at UZH, explained, "The identification of osteomyelitis, a painful infection of the bone tissue, marks a significant advancement in our understanding of dinosaur health and diseases. This particular case is notable due to the extensive nature of the infection, affecting both the shoulder and upper arm bones."

To explore the extent of the infection, researchers employed advanced imaging techniques, including computed tomography (CT) scans conducted at the Swiss Federal Laboratories for Materials Science and Technology (Empa). These scans revealed that the affected bones exhibited rough textures and unusual shapes, indicative of the chronic condition. Jordan Bestwick, a postdoctoral fellow at UZH, highlighted that while osteomyelitis has been documented in other dinosaur specimens, the scale of infection in this Plateosaurus is unprecedented. He stated, "Most previous cases reported localized infections, making this extensive infection particularly unique."

The implications of this discovery extend beyond the individual dinosaur. It provides critical insights into the health challenges faced by prehistoric creatures and their adaptations to environmental stressors. The findings may also inform current understandings of bone diseases in living animals, including humans. Dr. Dupuis emphasized, "Understanding how these animals coped with diseases can illuminate the evolutionary pressures they faced."

The Plateosaurus skeleton, affectionately named "Teoplati" through a public competition, is now a centerpiece exhibit at the Natural History Museum of UZH. The exhibit not only features the dinosaur's skeleton but also includes a life-size reconstruction that visually narrates its tragic story. This display is one of the few globally that incorporates pathological features into the presentation of a dinosaur, offering a unique educational opportunity for visitors.

The collaboration between various institutions underscores the importance of interdisciplinary approaches in paleontological research. Dr. Robert Egan, an associate editor involved in the review process, noted, "This research exemplifies how modern technology can enhance our understanding of ancient life and health, bridging the gap between paleontology and medicine."

As researchers continue to analyze the implications of this discovery, the findings are expected to contribute to broader discussions about the health of prehistoric ecosystems and the resilience of life in the face of adversity. The ongoing study of fossilized remains will likely reveal further insights into the life and challenges of dinosaurs like Plateosaurus, enriching our understanding of Earth's biological history. This investigation not only informs the scientific community but also captivates public interest in the mysteries of the distant past, highlighting the relevance of paleontology in contemporary science.

The research team plans to conduct additional studies to explore the origins of the infection further and its potential connections to environmental factors of the Triassic period. Their work exemplifies the dynamic nature of paleontological research, continually reshaping our understanding of ancient life forms and their interactions with their environments.