A new dinosaur fossil at the Denver Museum of Nature & Science was found buried hundreds of feet under the facility’s parking lot in January, making the herbivorous animal’s remains the oldest and deepest dinosaur fossil ever discovered in the city.

Museum crews came across the partial-bone fossil while conducting a geothermal drilling test to look at switching from natural gas to geothermal energy, officials said Wednesday.

A research team was looking at the material removed during the drilling to better understand the Denver Basin’s geology when they realized a partial-bone fossil belonging to a 67.5 million-year-old dinosaur was among the rocks taken from 763 feet below the surface.

“This is a scientifically and historically thrilling find for both the museum and the larger Denver community,” Curator of Geology James Hagadorn said in a statement. “This fossil comes from an era just before the mass extinction that wiped out the dinosaurs, and it offers a rare window into the ecosystem that once existed right beneath modern-day Denver.”

This is a developing story and will be updated.

Get more Colorado news by signing up for our daily Your Morning Dozen email newsletter.