DENVER — Parking lot construction at Colorado’s Dinosaur National Monument unearthed new fossils last fall, the first discovery at the monument in more than 100 years, according to the National Park Service.

Monument staff discovered the fossils — which likely belong to the Diplodocus, a large, long-necked dinosaur — on Sept. 16 near the Quarry Exhibit Hall, according to a news release from the park service. Asphalt removal during construction exposed dinosaur-bearing sandstone.

The Quarry Exhibit Hall, also known as the “Wall of Bones,” showcases roughly 1,500 dinosaur bones from the Late Jurassic period, some dating back 150 million years, according to the park service.

Roughly 3,000 pounds of fossils and rock were removed from the site near the exhibit hall between September and October, park service officials said in the release. Scientists at the Utah Field House of Natural History State Park Museum are now working to clean and study the remains.

The work can be viewed in the museum’s fossil preparation lab, park service officials said. Some fossils from the excavation are already on display at the museum and in the Quarry Exhibit Hall.

“This location had not been excavated for fossils since the original excavations at the site ended in 1924,” National Park Service officials stated in the release. “Historic excavations were led by the Carnegie Museum from 1909 to 1922, the Smithsonian National Museum of Natural History in 1923 and the University of Utah in 1924. Dinosaur National Monument was established in 1915.”

Construction was paused after the fossils were discovered to allow paleontologists to assess and remove the fossils. The project was finished following the excavation, according to the release.

Dinosaur National Monument sits on the edge of northwest Colorado and northeast Utah.

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