Meet Dolly, the First Dinosaur Discovered With a Case of the Sniffles

Abnormal growths in its fossilized neck bones suggest that the long-necked dino suffered from a pneumonia-like illness

An illustration of a group of sauropods
By combining evidence from CT scans and comparing Dolly's modern bird and reptile relatives, researchers suspect that the irregular bone structures likely occurred as a response to a bacterial or fungal infection like chlamydiosis and aspergillosis in Dolly's air sacs. Woodruff et al. (2022) and Corbin Rainbolt

Dinosaurs that roamed the Earth 145 million years ago appear to have also suffered from cases of the sniffles just like us.

Researchers found evidence of a respiratory infection in the fossilized vertebrae of a young, long-necked sauropod, reports the Independent's Nina Massey. The dino—a diplodocid known as Dolly—may have suffered from a fever, a runny snout, and a cough that would have shaken its muscular neck. The illness was so severe that a secondary infection appears to have developed in its bones, leaving visible evidence in its fossilized remains, reports Genelle Weule for Australia's ABC News.

Previous research has found that dinosaurs suffered from cancer, gout, and infections from injuries, but this study presents the first fossil evidence of a respiratory infection in a non-avian dinosaur, CNN's Ashley Strickland reports. The study was published this week in Scientific Reports.

Dolly was unearthed in 1990 in Montana. Paleontologists recovered a complete skull and some neck vertebrae. Analysis of the bones found that Dolly was between 15 and 20 years old when they died, reports CNN. When researchers took a closer look at three of Dolly's neck bones in 2018, they found bony, "broccoli-shaped" outgrowths, reports Riley Black for National Geographic.  

Cary Woodruff, a paleontologist at the Great Plains Dinosaur Museum in Montana, had seen other anomalies in sauropod vertebra before but had never seen anything like this. According to the Independent, the growths appeared in areas where they would have attached to air-filled sacs that made up the dino's respiratory system. 

Woodruff then took to social media to ask other colleagues about the abnormal growths and got immediate responses from other avian and reptile experts who compared the marks to an illness seen in reptiles and birds alive today called airsacculitis, which describes inflammation in the air sacs caused by viruses or bacteria, per National Geographic.  

From CT scans and comparison to other diseased animal bones, the researchers suspect airsacculitis was a respiratory response to a bacterial or fungal infection like chlamydiosis and aspergillosis, which later caused an infection in the neckbones, per ABC News. These respiratory infections are seen in birds and reptiles today and can lead to bone infections, per CNN.

Sauropods are more closely related to birds than any other dinosaurs, and researchers suspect that they share similar anatomical traits like their complex respiratory systems, per ABC News. Sauropods had air sacs near and in their bones like modern birds do. If Dolly had an aspergillosis-like infection, they would have experienced flu-like symptoms like weight loss, fever, coughing, and difficulty breathing, the Independent reports.

"We've all had many of the same symptoms and likely felt just as crappy as Dolly did," Woodruff said to National Geographic. "I don't personally know of any fossil I've been able to sympathetically relate to more."

How Dolly got sick in the first place is another point of interest. The humid environment in Montana 150 years ago could have contributed to fungal infection, and the sauropod could have breathed in spores or caught it from another member of their herd, per CNN.

Modern birds usually catch infections from cramped conditions. During nesting season, when dinosaurs were closer together, infections could have spread like wildfire, National Geographic reports. Overall, the research could help paleontologists trace the evolutionary history of respiratory infections in dinosaurs and the kind of diseases they were susceptible to. 

It is unknown if the illness itself was the cause of Dolly's death, but aspergillosis, if left untreated, is fatal to modern birds.

"We don't know whether Dolly could've just tipped over dead one day or was on its own and so visibly sick, making an easy target for a predator. But either way, I do think it ultimately led to the death of the animal," Woodruff explained to ABC News.