New Delhi: Some 150 million years after the Jurassic Period, scientists have discovered how an adolescent long-necked dinosaur presumably died in what is now southwest Montana in the United States after being sick with flu and pneumonia-like symptoms. The skeletal remains of the animal suggest it might have felt feverish and lethargic as it coughed, sneezed with laboured breathing and diarrhoea, news agency Reuters reported.
It is the first time that skeletal remains have represented evidence of respiratory illness in a dinosaur. Scientists have said the remains of the animal, now nicknamed ‘Dolly’, showed “abnormal growths resembling fossilized broccoli on three neck bones that formed in response to an infection in air sacs linked to its lungs”, the Reuters report said.
According to the scientists, Dolly appeared to have suffered from a fungal infection similar to aspergillosis, which is a common respiratory illness that sometimes causes bone infections and often turns fatal for modern birds and reptiles. Dolly’s death could have occurred due to this condition, though it is not uncommon for sick animals to not die directly from disease but due to starvation or other reasons.
The study was published in the Scientific Reports journal.
"Poor Dolly. She probably felt terrible with all the same signs and symptoms of a lower respiratory infection that we experience, such as fever, tightness in the chest, labored breathing, a productive cough - eew!" anatomist and study co-author Lawrence Witmer of the Ohio University Heritage College of Osteopathic Medicine was quoted as saying.
Aspergillosis is caused by inhaling spores from a fungus, and it is the most common respiratory infection today in birds.
About Dolly, The Dinosaur
Dolly was a plant-eating sauropod dinosaur with long necks, long tails, small heads and four sturdy legs. The scientists said it appears closely related to the well-known Diplodocus species, but a future study will reveal the scientific name of Dolly's species.
About 60 feet (18 metres) long, Dolly perhaps weighed 4 to 5 tonnes and was between 15 and 20 years of age at death, said Cary Woodruff, director of paleontology at the Great Plains Dinosaur Museum in Malta, Montana, and lead author of the study.
Sauropods reached adulthood in their late 20s, the study said.
"Was Dolly so sick that she couldn't keep up with the herd? Did she die from this disease? Did she die alone? We know that she was sick for a long time - it was a chronic disease - because she had it long enough for her bones to respond with nasty reactive bone growth," Witmer said.
"...as scientists we're excited and intrigued by Dolly's disease, but as humans who love dinosaurs and another animals, our hearts break when we think about how the last days of this young dinosaur were spent ill, groggy, maybe surrounded by ferocious predators like Allosaurus," he added.
It was in 1990 and in 2013-2015 that Dolly's remains were unearthed. The researchers do not yet know Dolly's gender. They nicknamed the dinosaur after a famous singer.
"Dolly Parton, of course," Woodruff said.
"I don't personally know of any fossil I've been able to sympathetically relate to more," he said.
Why This Study Is Important
While all dinosaurs may have suffered from diseases like any other animals, there is little evidence of this in the fossil record. Dinosaur fossils have in the past shown broken and healed bones, arthritis, tooth abscesses, blood-borne infections affecting bone, and even bone cancer, the report said.
Besides shedding light on medical conditions in deep time, Dolly's case also provides insight into the anatomical structure of dinosaur lungs and air sacs, the study said.
According to scientists, respiratory tracts found in sauropods and theropods, the meat-eating dinosaurs, were far more elaborate than in mammals including people. In addition to lungs, they were said to have thin, balloon-like air sacs that “invade the body cavity and many bones”.
In Dolly, the scientists found abnormal bone growths at the connection between respiratory tissue and bone in three vertebrae, which was proof that the infection had spread from the lungs.