The fossilized upper molar and canine were found in the late 1970s in coal deposits and kept in the collection of the Bulgarian National Museum of Natural History for more than four decades.
“They only had one vaguely handwritten label,” said Nikolai Spassov, a professor at the museum and author of a new study on teeth, in a press release. “It took me many years to figure out what the locality was and how old it was. Then it also took me a long time to realize that it was an unknown fossil giant panda.”
“This discovery shows how little we still know about ancient nature and also demonstrates that historical discoveries in paleontology can lead to unexpected results even today,” he said.
While pandas are best known by their sole living representative, the giant panda, there were once a range of related species that roamed Europe and Asia.
The species discovered through the museum’s artifacts was the last known panda to live in Europe, according to the press release. The researchers named it Agriarctos nikolovi after the museum’s longtime paleontologist, Ivan Nikolov, who originally cataloged the find.
The study found the bear to be as large as the modern giant panda or slightly smaller. It probably ate a mostly vegetarian diet, but its meals would have been more varied than those of the panda’s only living relative, who eats only bamboo. The cusps of the teeth were probably not hard enough to crush the bamboo’s woody stems, suggesting that the animal would have eaten softer plants, according to the research.
The coal deposits in which the teeth were found provided evidence that this ancient panda inhabited forested and swampy regions. Spassov and his co-author Qigao Jiangzuo, a panda specialist from Peking University in China, proposed that the panda may have become extinct during an event in which the Mediterranean basin dried up, transforming the surrounding environment.
“Giant pandas are a very specialized group of bears,” Spassov said in the statement.
“Even though A. niklovi was not as specialized in habitats and food as the modern giant panda, fossil pandas were sufficiently specialized and their evolution was linked to moist and forested habitats,” he said. “It is likely that climate change at the end of the Miocene in southern Europe, leading to aridification, had a detrimental effect on the existence of the last European panda.”
The Miocene epoch was 23 to 5 million years ago.