The Denver Museum of Nature & Science already houses a vast trove of dinosaur bones, but it recently received an unexpected addition to the collection. The latest fossil didn’t come from a generous benefactor or anonymous donor–it came from beneath the museum’s own parking lot.

The team began drilling over 763 feet below the museum's parking lot when they came across a "major dinosaur discovery," the museum said on Facebook. Researchers found an "ancient bedrock from the Late Cretaceous Period," which didn't shock scientists – until they learned it contained a 67.5-million-year-old partial dinosaur bone, officials said.