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When the digging is all done and the bones have all been collected, the Thornton triceratops discovered under a public safety substation construction project in August might be one of the most complete skeletons of its kind, according to paleontologist Joe Sertich.
Sertich, curator of dinosaurs for the Denver Museum of Nature & Science, has been front and center at the 132nd Avenue and Quebec Street dig site, helping to uncover the 66 million-year-old fossilized skeleton and communicating with the world what the diggers are finding.
Sertich hosted a live video feed at the site for hundreds of Colorado schools on the morning of Sept. 2. That afternoon, he took a few of the bones to nearby Brantner Elementary, a few hundred feet from the dig site, and showed to them to school’s students and teachers.
The bones may be a common thing in the Colorado soil, Sertich said. The finds, however, are not so common.
“They are just not exposed very well,” Sertich said Sept. 2 after he took questions from Brantner students. “If we had badlands in this area, we’d have more dinosaur fossils, probably, than anywhere in the Western U.S. It’s only when we scrape down to them during construction that they show up. These fossils are probably being scraped into regularly, but people don’t know it. If you’re 10 feet above the ground in a bulldozer, you can’t be sure of what your hitting.”
Luckily, that’s not what happened in Thornton. A bulldozer driver preparing the site at 132nd and Quebec for new public safety substation hit the first bone Aug. 25 and immediately stopped work, contacting his supervisors and then the museum.
Museum staff arrived at the site Aug. 28 and have been digging ever since, uncovering hundreds of bones and bone fragment and happily showing them off to local and national media.
What they’ve found is the remains of a juvenile triceratops, one of many that wandered this area near the end of the Cretaceous period. Sertich said it’s likely the animal died and was set upon by scavengers, including tyrannosaurs and smaller dinosaurs. That theory was bolstered by the find Sept. 7 of a banana-sized T-Rex tooth mixed among the triceratops bones.
Sertich said the bones, the skull and ribs and legs they’ve found are smaller than normal, leading experts to agree they’ve found an immature specimen.
“We can actually cut open their bones and count the rings, like the rings on trees, and tell their age,” Sertich said. “This one was actually only 10 or 15 years old, based on the size of the bones. But we’ll know more when we study it more.”
Triceratops are most common dinosaur fossils around, and Sertich said they were common in the Midwestern plains, especially in northern U.S. states like Montana and North Dakota.
Colorado, and especially Thornton, represent the southern boundary of that range.
“We have another triceratops from Brighton, not very far from here, that was found in 2003,” Sertich said.”It was the same thing, a construction project was out and crews were clearing the area and they hit it, breaking it in half. But this one is better because it wasn’t hit. We found it and preserved it almost perfectly.”
It’s a significant find — and a welcome one for Sertich, who spend his time traveling to similar digs around the United States for the museum. He said he’s heading to an excavation in Utah when he wraps up on Thornton.
“That site is a 12-hour drive away, 20 miles from the nearest road and way in the backcountry,” Sertich said. “So it’s really nice to be just 30 miles away from home.”
Bones keep coming
Museum communications and media relations manager Maura O’Neal said the wrapup in Thornton may be a ways off. Crews continue to find bones at the site, wrapping them in plaster and taking them to museum. She said between the bones still in the ground and bones back at the museum, museum staff has more than a year’s worth of work, processing the Thornton find.
“That’s what it would take to get everything collections-worthy, so to speak,” O’Neal said.
She didn’t know how much longer work would go on at the site.
“There are still bones in there, but they have not been exposed so we don’t how many and of what are in there,” she said. “So, there is still more to come.”
City of Thornton officials said work should not delay the opening of their public safety substation. Crews officially broke ground on the 30,000 square-foot substation July 31, but moved the work to a different location on the site when the fossil was found.
“We don’t anticipate the removal impacting the opening date at this point,” said Jerry Dye, Thornton support services director.
Police warned residents that the site is closed.
“We have not had anyone trying to sneak into the site, but have had a lot of curiosity seekers and people ask if they can access the site,” Thornton officer Matt Barnes said in an email. “They have all been cordial and polite encounters. We understand this is a unique discovery and something that most people would never get a chance to see or experience in their lifetime.”
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