Museum workers found a T. rex tooth among the triceratops fossils on Thursday as they excavated prehistoric artifacts from a construction site in Thornton.

The T. rex was likely scavenging and came across the dead triceratops. But the excavators don’t expect to find any more of the large dinosaur — T. rex teeth sometimes fell out as they chowed down.

The Denver Museum of Nature & Science announced the discovery Friday during a press conference where workers opened a plaster cast used to transport the fossils, showing off the horn that alerted construction workers to the presence of the triceratops.

Saunders Construction workers noticed an inch or half of the bone on Aug. 25, and immediately shut down their earth-moving machines. The museum’s dinosaur curator Joe Sertich said he visited the site the following Monday, expecting to find a couple of small chunks of bone. But within 30 minutes, he found three or four other fossils.

“I think I had a heart attack on the site,” he said, jokingly adding, “We had to pull in some medical help.”

Workers have found about three-quarters of the triceratops skull along with its horns, jaw, jaw beak, frill, shoulder-blade, vertebrae, ribs and humerus. They don’t expect to find all of the bones as most animal skeletons are scattered after death by scavengers — such as a hungry T. rex — or water before they’re buried and fossilized.

Although this is the most complete triceratops found on the Front Range, but it’s not enough to tell if the creature was male or female. It is clear, though, the dinosaur was not fully grown. The first triceratops ever found was unearthed in Denver in 1887. Triceratops found along the Front Range are smaller than those found in the Midwest that could be 20 to 30 feet long and up to 8-feet tall.

“This is really the story of the Front Range and I want you all to go out and start digging in your backyard so we can find more of those things,” Sertich joked.

Crews are still at the construction site but the museum thinks they’ll be wrapping up soon. The city of Thornton and Saunders Construction aren’t overly concerned that the timeline for the fire and police station will be disrupted.

“It’s really exciting that they put (the fossil) ahead of the project because it’s monumental for the city of Thornton,” mayor Heidi Williams said.

It helps that the dig is confined to all 20-foot by 20-foot portion of the construction site, allowing for construction to continue in other areas.

David Ortiz brought his 4-year-old son Daniel to the museum from Aurora to check out the fossil after hearing about it on the morning news.

“You think they’re up in Alaska or Wyoming or up north,” David Ortiz said. “Here was really surprising.”

Daniel Ortiz, who is a big dinosaur fan, wore a shirt showing off the prehistoric creatures, including a triceratops. He said his favorite dinosaur was a T. rex. When asked why, he bent to the ground and then lifted his hand up in the air: “T. rexes — they’re like this big.”

It’ll take a year to prepare the fossils for research and presentation. But interested folks can see some of the fossils as museum volunteers clean them in the paleontology lab.