COVID-19 and influenza have caused pandemics (global epidemics). Bacteria and viruses have long threatened humanity in the form of infectious diseases. Recent fossil research has revealed that Jurassic and Cretaceous dinosaurs, like humans, suffered from various infectious diseases. Dinosaurs are the ancestors of modern birds. The infectious diseases that plagued their ancestors continue to plague birds today in the form of avian influenza. The disease plaguing these birds was a respiratory infection. In 2022, the Great Plains Dinosaur Museum in the United States announced that it had found evidence of “air sacitis.” An abnormal proliferation of bones, also seen in birds with air sacitis, was found inside the cervical vertebrae of a fossil. This air sacitis is a disease in which the air-retaining organ becomes inflamed. In humans, this condition may lead to pneumonia.
In another example, researchers at the Regional University of Cariri in Brazil examined fossils believed to be leg bones of a long-necked sauropod. They examined fossils believed to be leg bones of a long-necked sauropod that lived during the Cretaceous period of the Mesozoic era. The Cretaceous period follows the Jurassic period, approximately 105 to 66 million years ago. This period is thought to be the heyday of dinosaurs. Microscopic analysis of the fossils revealed bones that had become spongy due to inflammation. It is believed that the spongy tissue showed no signs of healing. It is highly likely that the dinosaurs died as bacteria multiplied, worsening the symptoms. Other dinosaur fossils bearing signs of osteomyelitis have been found in the same locations that these fossils were unearthed. It is believed that these locations were the site of “mudgy water that accumulated during the dry season.” Dinosaurs gathered in large numbers in search of water, competing for the scarce water. It has been suggested that bacteria that thrived in the few puddles may have infected dinosaurs living near water, causing osteomyelitis.
The research field that analyzes fossil proteins is called “paleoproteomics.” This field of research is useful for clarifying the phylogenetic relationships of extinct animals. Protein analysis techniques are also making great strides. Currently, we are working on research to search for proteins and other organic matter in dinosaur fossils. By examining the proteins of infected dinosaurs and dinosaurs with cancer, we may be able to understand the path that pathogens took in the subsequent evolution of those pathogens. Sun Tzu once said, “If you know your enemy and know yourself, you need not fear the consequences of a hundred battles.” If we know the strengths and weaknesses of viruses and bacteria, humanity may have a better chance of victory.
