The progressive bone damage was probably painful and severely inflamed. “These lesions could have been related to muscles and skin and have been exposed so that blood or pus escaped,” explains Aureliano.
What disease was it?
Common to all deformed bones that they have no traces of healing. “This means that the animals died with even active infection – probably from the consequences of the disease itself,” says Aureliano. In order to find out exactly what infection it was, the team first checked various diseases that can cause bone changes.
The paleontologists were able to rule out bone cancer because the typical spiky structures in the bone are missing. Tuberculosis -like infections also did not fit into the picture, since the bones do not show any corresponding symptoms. Arthrosis was also out of the question, because the affected areas are not due to joints, but on ribs and limbs. Only one diagnosis matched all observed characteristics: osteomyelitis, a bone inflammation triggered by bacteria, viruses, mushrooms or protozoa.
This infection can spread inside the bone or in the outer layers and the surrounding tissue. Typical are spongy areas, growths and a quick progress that hardly leaves time to heal. Nowadays, osteomyelitis causes severe pain and can even be fatal – a fate that may also have hit the long -necked dinosaurs from São Paulo.
Contaminated drinking water as the cause?
But how could several sauropods be infected with the aggressive bone inflammation at the time? The paleontologists suspect that the Savanne -like region played a role in which the long -necked dinosaurs lived 80 million years ago. There was a dry climate there and there were numerous flat, slowly flowing rivers and large standing waters, as the paleontologists report.
“This environment probably favored pathogens that may have been transferred by mosquitoes or by the water drank by the animals, including dinosaurs, turtles and animals that resemble today’s crocodiles,” explains Aureliano. In theory, the pathogens could have penetrated external injuries such as bites or breaks, but the team did not find any signs for that. (The Anatomical Record, 2025, DOI: 10.1002/AR.70003)
Quelle: São Paulo Research Foundation (FAPESP)
4. September 2025
– Anna Manz
