With a young dinosaurs, experts have probably been able to demonstrate the traces of a respiratory infection for the first time. On the vertebrae of the sauropoden, who died around 150 million years ago, a team led by D. Cary Woodruff from the University of Toronto found damage and adhesions in those areas of the bones that bounded to the animal's breathing tract. As the working group reports in the "Scientific Reports", most evidence suggests that the changes come from a disease that corresponds to luminatitis in modern birds. The cause may have been chlamydia or mold of the genus Aspergillus; Both still cause flu -like and occasionally fatal respiratory infections in birds.
The skeletal parts found in 1990 in the US state of Montana – the skull and seven cervical vertebrae – probably belonged to a dinosaur related to Diplodocus. Its neck was traversed by a system of air sacs connected to the lungs and belonging to a respiratory tract that probably resembled that of modern birds. For this reason, the working group uses their diseases as a comparison to determine the cause of bone damage. For example, some tumor diseases cause damage to bones in birds, and cancer has been detected several times in dinosaurs. However, Woodruff's team considers this to be the less likely possibility: On the one hand, tumors in the air sacs are rare in birds, and on the other hand, they usually cause damage to one bone, not several.
Another option would be a non -infectious inflammation of the airways, for example through inhaled dust or volcanic ash. However, there is no traces of a volcanic eruption, and beyond that, dust blame is such a rare type of death in wild animals that the team rejects this variant for statistical reasons. The last possible explanation of the damage remains luminatitis, a respiratory infection by bacteria or fungi. Both occur frequently in modern birds. The disadvantage of this explanation: In modern birds, such infections practically cause damage to the soft tissue. According to the working group, bone changes only occur in tuberculosis, triggered by mycobacteria. On the other hand, however, speaking that these changes look significantly different than the findings from the dinosaurs from Montana.
For this reason, Woodruff's team favours other respiratory infections that are very common in birds as an explanation – for example with chlamydia, the triggers of parrot disease, or moulds of the genus Aspergillus. The latter cause a fungal disease called aspergillosis not only in birds, but also in many other animals and humans. The region was warm and humid during the animal's lifetime, argues the working group, so it is tempting to see the mold as the cause of air sac inflammation. There is only one small catch: Whether Aspergillus or similar fungi already existed at that time is unclear. The oldest known spores of this genus are almost 100 million years younger than the coughing dinosaur.
