Left to Right: James Hagadorn and Bob Raynolds examining a drilling core from the City Park core drilling in the parking lot at Denver Museum of Nature & Science.
Photo by: Rick Wicker

A dinosaur fossil described as the deepest and oldest one ever found within the city of Denver is now on display at the Denver Museum of Nature & Science after being discovered under the museum’s parking lot in City Park.

The discovery was made as a museum team was conducting a geothermal test drilling project to determine the viability of transitioning from natural gas to geothermal energy. At the same time, scientific coring was done to better understand the geology of the Denver Basin.

The coring led to the discovery of the partial bone fossil 763 feet below the surface.

“This is a scientifically and historically thrilling find for both the museum and the larger Denver community,” James Hagadorn, curator of geology at the museum, said in a news release. “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.”

Ornithopod vertebra from the Denver Formation, from 763′ of depth in the City Park core drilling in the parking lot at Denver Museum of Nature & Science. Photo by: Rick Wicker

Patrick O’Connor, director of earth and space sciences at the museum, was part of the team that identified the bone as a vertebra of a plant-eating dinosaur. O’Connor said the bone was found in Late Cretaceous rocks dated to about 67.5 million years ago. He added that this may be the most unusual dinosaur discovery he’s ever been a part of.

The work being done in the parking lot was part of a $250,000 grant from Gov. Jared Polis’ Geothermal Energy Program at the Colorado Energy Office.

The fossil is now on display on the museum floor in the “Discovering Teen Rex” exhibition.