We all remember the mythical scene from Jurassic Park in which Dr. Alan Grant, Tim and Lex, up a tree, feed a huge Brachiosaurus . During the fun interaction, the child, very observant, notices that the animal is breathing with difficulty. “Looks like she has a cold,” he says, seconds before the female sauropod sneezes at Lex, who is covered in dinosaur snot.
“Cheers, girl!”
The scene is one of the funniest moments in the film, in which the protagonists interact with a harmless dinosaur. A moment where they can relax and let their guard down after many high-tension scenes. But how faithful is this to reality? Could dinosaurs really get colds or colds?
What is a cold?
The cold, also called the common cold , is a normally mild and very common respiratory infection that mainly affects the upper airways. It presents with abundant mucous secretion, nasal congestion, hoarseness and sneezing. Less frequently, it is accompanied by a sore throat, headache, cough, muscle aches, or decreased appetite.
Contrary to popular belief, colds are not caused by exposure to cold or water. The cause of the cold is viral , and is transmitted through tiny drops and aerosols that are expelled, above all, with sneezes and coughs, directly or through fomites. A fomite is any inert object or surface contaminated by the pathogen. Any healthy person who touches such a surface, and then touches their mouth, nose, or eyes, becomes infected with the virus.
There are many viruses that cause colds. More than half are produced by up to 115 varieties of a family called rhinoviruses . Others are caused by coronaviruses —much milder than the one that causes COVID-19, but from the same family—, adenoviruses, enteroviruses, influenzaviruses —of the flu—, parainfluenzaviruses, and respiratory syncytial virus.
cold birds
To find out whether or not dinosaurs like Brachiosaurus could catch colds—or suffer illnesses analogous to our common cold— it makes sense that we look at birds . Since they are dinosaurs, if birds can get colds, then we know that at least one group of dinosaurs can get these kinds of respiratory illnesses.
Although the symptoms are not always the same, there are quite a few viruses that can cause upper tract infections in birds that are similar to human colds.
Among the reovirus family, infections that cause rhinitis are common; varieties of bird flu also stand out, some can jump to humans in the form of zoonoses. Some varieties of fowlpox can cause mild respiratory infections and laryngitis.
But when we talk about “dinosaurs”, we usually refer to those huge Mesozoic animals, which became extinct 66 million years ago. Those that in science are called non-avian dinosaurs, to distinguish them from birds. So could these non-avian dinosaurs catch colds?
The answer lies in fossils
As usual, questions about extinct non-avian dinosaurs often find their answer in the remains they left behind. But in this case it was not an easy answer to obtain.
In the bones we can find evidence of repaired fractures, deep wounds that affect the bone, and certain diseases such as bone inflammation or arthritis. However, making a diagnosis of diseases that do not directly affect the bones is very complicated when only the fossil record is available.
First of all, it is not possible to carry out a veterinary test on an animal that died millions of decades ago; secondly, it is unlikely that the affected soft tissues will be preserved, and finally, when bone lesions caused by these diseases occur, they are generally nonspecific and do not allow a sufficiently precise diagnosis.
But just because it’s very complicated doesn’t mean it’s impossible .
Sauropods had a fairly complex respiratory system, with air sacs, like modern birds, that extended inside the bones , lightening their weight. A recent study, led by the paleontologist Cary Woodruff and published in the journal Scientific Reports , dependent on the highly prestigious Nature , managed to prove the existence of lesions in the cervical vertebrae, derived from conditions in these air sacs in a diplodocid sauropod skeleton . These lesions were compatible with a respiratory-type infection, specifically, aerosarculitis with associated osteomyelitis .
These types of diseases in birds are generally caused by bacteria or fungi. In the fossil it was not possible to identify the infectious agent. And therefore, we cannot guarantee that it was a disease analogous to our cold. Supposedly, it must have been much more serious than a cold.
The question that heads this article, therefore, has not yet been answered by science, although the probability that it is affirmative is quite high. In any case, this research opens the door to new ways of understanding and diagnosing diseases that could affect non-avian dinosaurs, and perhaps in a few years, we will know for sure whether or not they really could catch colds.
References:
Esteva, E. 2001. Common cold. Offarm, 20(11), 57-65.
Tully, T. N. 1995. Avian Respiratory Diseases: Clinical Overview. Journal of Avian Medicine and Surgery, 9(3), 162-174. DOI: 10.2307/30134458
Vorvick, LJ et al. sf Common cold ( No. 000678; MedlinePlus).
Woodruff, D. C. et al. 2022. The first occurrence of an avian-style respiratory infection in a non-avian dinosaur. Scientific Reports, 12(1), 1954. DOI: 10.1038/s41598-022-05761-3
