Park staff say the discovery near the Quarry Exhibit Hall is the first fossil excavation there since 1924, when the original excavations at the site ended.
Staff identified the bones back in September 2025 and stopped construction for paleontologists to assess and excavate the fossils.
Scientists believe the bones belong to the large, long-necked dinosaur Diplodocus from the Late Jurassic period, which are common in the area.
Roughly 3,000 pounds of fossils and rock were removed between September and October.
Experts are now studying the bones at the Utah Field House of Natural History State Park Museum in Vernal.
Fossils from the excavation are also on display at the Quarry Exhibit Hall, one of Dinosaur National Monument’s most popular areas. The hall is built over a preserved section of the historic Carnegie dinosaur fossil quarry and displays about 1,500 dinosaur fossils still encased in the rock.
