A diner sitting in the outdoor courtyard of a small restaurant in China's Sichuan province happened to look down at the ground and spot something unusual. It appeared to be a dinosaur footprint.
Earlier this month, Chinese paleontologists confirmed that the diner was right. The depressions had in fact been left by two dinosaurs as they plodded across the region about 100 million years ago.
Using a 3D scanner, scientists determined that the tracks were made by sauropods, large herbivorous dinosaurs with long necks and four legs. According to Lida Xing, a paleontologist at China University of Geosciences who led the team investigating the site, the footprints were probably made by the species Titanosauriformes.
The footprints are about 22 inches long on average, and the dinosaurs probably measured about 26 feet long and weighed more than 2,000 pounds, Xing told The Washington Post.
While not an everyday occurrence, the discovery of dinosaur footprints happens on occasion in China, just not in urban environments.
"Sauropod tracks are not rare in Sichuan Basin ... but they are very rare[ly] found in restaurants in downtown," Xing said in an email. "Most of the time, the ground of the city is either vegetation or cement."
But it wasn't the first accidental discovery of dinosaur remnants in recent years.
Take, for example, the case of Mark McMenamin, who was walking across the campus of the University of Massachusetts at Amherst last year. He and his wife collected stones at a construction site, then later noticed one of them appeared to be a fossil.
It was, in fact, the elbow bone of a 30-foot-long predatory dinosaur known as a neotheropod. McMenamin, a professor of geology at Mount Holyoke College in Massachusetts, estimated the Jurassic fossil to be between 145 million and 200 million years old, Newsweek reported.
Then there was the discovery of a well-preserved dinosaur "corpse," unearthed by miners in Canada. While excavating at the Suncor Millennium Mine in Alberta in 2011, they stumbled upon the fossilized remains of a Nodosaurus, a heavily armored creature dating to about 110 million years ago, according to National Geographic.
Displayed for the first time in 2017, it is considered one of the best-preserved dinosaur fossils ever found. So complete are the remains that scientists at the Royal Tyrrell Museum in Alberta were able to examine the contents of its stomach, including twigs, leaves, mosses, pollen and spores.
Last year, archaeologist Marie Woods was looking for clams on the beach in Yorkshire, England, when she spotted something unusual: the 165-million-year-old footprint of a species of theropod. A dinosaur similar to a Tyrannosaurus rex, this ancient reptile also stood on two legs and was carnivorous. It was the largest footprint of its kind ever found in that part of England, reported the Good News Network.
"All I wanted to do was grab some shellfish for my dinner and I ended up stumbling across this," Woods told the website.
In 2011, paleontologists in China encountered a big rock with a fish fossil on the surface. They hauled it back to the lab, where it sat for about a year, according to New Scientist. Then the researchers decided to crack it open.
To their amazement, they discovered inside the remains of a mother ichthyosaur, a fishlike creature that swam in the oceans during the Mesozoic Era 252 million to 66 million years ago, giving birth to three babies. One was already out of the womb, another was halfway out, and the third was waiting for its chance.
This fossil find altered the view of when dinosaurs began having live births, pushing back the historical record by nearly 250 million years. Ichthyosaurs, which evolved from land-based creatures, proved that dinosaurs had moved on from egg-laying much earlier than previously believed.
"This land-style of giving birth is only possible if they inherited it from their land ancestors," one of the researchers told Live Science. "They wouldn't do it if live birth evolved in water."
Back at the restaurant in Sichuan province, Xing and her team continue to study the accidental discovery of the dinosaur tracks. The area where the sauropod footprints were noticed has been roped off so curious diners won't accidentally harm them.
At first, the restaurant owner was anxious that news of the primordial find would affect her business serving homestyle meals based on local cuisine. However, she has since embraced the media hype.
"She was initially concerned that she would attract a lot of curious people and affect the restaurant's traditional customers," Xing wrote. "But now she understands the change and is ready to roll out some dinosaur track-themed treats."