Researchers have uncovered the 245 million-year-old remains of a marine reptile that was infected by a disease similar to modern-day tuberculosis.
The skeleton of a Proneusticosaurus silesiacus was unearthed at the Gogolin quarry at the border between Poland and Czech Republic, a site well-known for its numerous sea reptile fossils.
Researchers found tiny, rough protrusions called blebs in the reptile's ribs, similar to bumps found in patients of modern-day tuberculosis.
Proneusticosaurus silesiacus is a member of the sauropterygian family of aquatic reptiles that flourished the Mesozoic Era. They are a cousin of the plesiosaur, a long-necked sea reptile with lengths spanning up to 40 feet.
This particular species was a smaller, slenderer breed. It had a flat skull, a long neck, and long, rounded teeth. It most likely moved by undulating its body or paddling with its limbs. Proneusticosaurus lived in the Triassic period some 251 and 199 million years ago before the onset of the Age of Reptiles.
Several specimens of sea reptiles were collected at the Gogolin quarry, most of which are now housed at the University of Wroclaw's Museum of Geology. Much of them, however, had seen extensive damage during World War II. The specific specimen taken as part of the study was also partly damaged. Thankfully, the middle part of its body, where the ribs are found, was preserved.
Oldest Tuberculosis Case
After ruling out a number of different causes for the protrusions, including fractures, fungal infections, scurvy, and cancer, scientists were able to conclude that the blebs are a sign of tuberculosis.
In their study published in the Royal Society Open Science, the researchers note that the blebs were most likely caused by pneumonia, which is often associated with tuberculosis.
They also note that Proneusticosaurus led similar lives to modern seals. Both animals dive into the depths of the sea for food and haul themselves up onto the land. Interestingly, seals are the most susceptible to tuberculosis, the researchers say.
This makes the Proneusticosaurus the world's oldest case of tuberculosis, taking the record from a 3 million-year-old marsupial.
Tuberculosis In Animals
Tuberculosis is caused by an infection of the bacteria Mycobacterium tuberculosis. It affects mostly the lungs, but in some cases, the infection spreads to the spine, kidneys, and brain.
Up to 1.7 million people succumb to tuberculosis every year. However, the disease has also wreaked havoc on animals.
"Modern-day epizootic studies of the spread in free-ranging animals have been reported for birds and mammals," says paleontologist and principal author Dawid Surmik, "but data regarding reptiles are scarce."
It is clear from the study that the reptile survived several seasons before tuberculosis claimed its life. It is not known, however, if it died because the disease restrained its hunting abilities or due to the failure of internal organs.