A natural history museum in Denver famed for its dinosaur exhibits made a one-in-a-million discovery this week after a prehistoric fossil was found underneath its parking lot. While drilling a 750-foot borehole to assess geothermal heating potential at the Denver Museum of Nature and Science,

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.