The dinosaur age was supposed to have begun roughly 230 million years ago, but a new discovery pushes their genesis back 15 million years. Palaeontologists have long sought the earliest dinosaurs. Now, skeletal remains from a pair of fossils show that dinosaurs arose in the aftermath of the world’s largest mass extinction — the crash that occurred around the transition from the Permian to the Triassic periods roughly 252 million years ago.
The prehistoric world was hardly a disease-free utopia, but diagnosing old diseases is difficult since germs do not normally fossilize well. However, researchers have discovered evidence of what looks to be the oldest known respiratory ailment in a dinosaur.
A dinosaur fossil’s age can be determined in two methods. One method is to determine if one dinosaur specimen is older or younger than another using relative geologic time. The alternative method is known as absolute geologic time, and it entails estimating how many millions of years a dinosaur fossil is.
Lesions discovered in the vertebrae of a 150-million-year-old juvenile sauropod named “Dolly” allude to a lung illness that spread to her bones. This is at least 50 million years earlier than a previously recorded respiratory illness in a titanosaur discovered in Brazil.
Cary Woodruff
To calculate relative age, it is necessary to understand that dinosaur fossils are preserved in layers of sedimentary rock that are deposited sequentially, one on top of the other. Fossils found in an older, lower rock layer are older than those found in a higher, younger layer.
Sequences of rock layers holding dinosaur fossils frequently include layers of ancient volcanic ash, and the ash is made up of minerals crystals produced during the eruption that contain radioactive atoms. These atoms disintegrate at a steady rate in a process known as radioactive decay. Geologists can use advanced scientific tools to determine how long it takes for half of the parent atoms to disintegrate into daughter atoms, a time span known as the half-life. The fraction of parent and daughter atoms present in the ash crystals is then measured by geologists to establish the crystal’s age.
Lesions discovered in the vertebrae of a 150-million-year-old juvenile sauropod named “Dolly” allude to a lung illness that spread to her bones, report vertebrate paleontologist Cary Woodruff and colleagues in Scientific Reports. This is at least 50 million years earlier than a previously recorded respiratory illness in a titanosaur discovered in Brazil.
Dolly, a long-necked dinosaur, was most likely a near relative of Diplodocus. Woodruff estimates that she was roughly 18 meters long and fewer than 20 years old when she died in what is now southeastern Montana.
The scientists examined the dinosaur’s skull as well as the first seven neck vertebrae, which included air sacs connected to the lungs and other aspects of the respiratory system. Many of today’s birds, which are modern-day dinosaurs, have bones that resemble those of dinosaurs.
The investigators discovered bone lesions on the fifth through seventh vertebrae, where the air sacs would have intruded into the bone. According to Woodruff of the Great Plains Dinosaur Museum in Malta, Mont., the irregularly shaped and textured lumps protrude from the bone as much as 1 centimeter.
So many lesions appearing in identical locations are unlikely to be bone cancers, which are unusual in birds in any case, according to Woodruff. According to the study, the lesions originated as a result of a respiratory infection that traveled to the distal air sacs.
Though Dolly’s bone lesions would not have been visible to an ancient spectator, the scientists believe she suffered a fever, cough, hard breathing, and nasal discharge. It’s unclear whether the infection was bacterial, viral, or fungal, or whether it was the cause of Dolly’s death. However, the researchers point out that many birds and reptiles nowadays are susceptible to a respiratory illness produced by the fungus Aspergillus, which can lead to bone infections.
