Imagine digging under a parking lot and finding part of a dinosaur. That’s exactly what happened earlier this year at the Denver Museum of Nature & Science. Known for its impressive fossil collection and dinosaur exhibits, the museum wasn’t even looking for bones when this surprise came up.
In January 2025 while workers were drilling into the ground for a geothermal energy project something unexpected happened. A core sample pulled from 763 feet underground revealed a chunk of ancient bone, shaped like a small hockey puck. It was fossilized, hard as rock and completely hidden for millions of years.
“This wasn’t a fossil dig,” the museum explained. “It was part of a plan to make our heating and cooling system more eco-friendly.”
A “One-in-a-Million” Find
Dr. James Hagadorn, who oversees geology at the museum, was amazed by the find. He compared it to something nearly impossible—like making a hole-in-one from the moon or stumbling upon a golden ticket to the Willy Wonka factory. “It’s unbelievably rare,” he said.
The drilling was meant to check how deep heat from the earth could be used to power the museum. But it also gave scientists a unique chance to examine the Denver Basin — a deep underground area full of layers of ancient rock and history. And that’s where the fossil came from.
The piece of bone was later confirmed to be part of a vertebra from a plant-eating dinosaur that lived about 67.5 million years ago. That’s just before the asteroid impact that wiped out the dinosaurs. According to the museum’s experts, the fossil most likely belonged to an ornithopod, a type of bipedal herbivore similar to Thescelosaurus or Edmontosaurus. These dinosaurs were about 10 to 12 feet long, and lived in swampy, lush environments.
Patrick O’Connor, the museum’s curator of vertebrate paleontology, said, “This animal was living in what was probably a swampy environment that would have been heavily vegetated at the time.” So instead of the dry Colorado climate we know today, Denver was once warm, wet and packed with life.
More Than Just a Bone
This fossil may be small—but it carries big meaning. It’s the deepest and oldest dinosaur fossil ever found in Denver city limits. The core sample also contained pieces of fossilized plants giving scientists even more information about the area’s prehistoric past.
And while it’s just one piece, it helps fill in gaps about what kinds of dinosaurs once walked where we now drive and park.
“It provides direct evidence of the types of dinosaurs that roamed this specific area of North America during a critical geological period” the museum stated.
From Borehole to Exhibit
Now, this hockey puck-sized bone is on display at the museum, featured in the “Discovering Teen Rex” exhibit. It may not be as flashy as a full skeleton but it tells a powerful story. Visitors can see the actual fossil that spent millions of years buried beneath their feet—right under the museum’s north parking lot in City Park.
Still, don’t expect the museum to start digging up the whole lot anytime soon. “I would love to dig a 763-foot (233-meter) hole in the parking lot to excavate that dinosaur, the rest of it. But I don’t think that’s going to fly because we really need parking,” said Hagadorn with a laugh.
This rare discovery shows how science can show up in the most unexpected places. Beneath the everyday world—beneath our streets, our buildings, even our parking lots—there’s still a lot of ancient history waiting to be uncovered.
According to Rocky Mountain PBS, this fossil may be small, but it’s an important reminder that the past is always present—just deeper than we usually dig.
