To celebrate the reopening of the Museum’s Prep Lab in 2011, we worked on an exciting sandstone block from Utah that was collected in the early 1900s at what is now Dinosaur National Monument. From the beginning, we knew that we had some type of dinosaur encased in the rock, but which one? By September 23, 2012 - the one-year anniversary of working on the specimen - we'd exposed enough of the bones to announce that our mystery dinosaur fossil was the first seven tail vertebrae from an Apatosaurus!

Apatosaurus was one of the long-necked dinosaurs that roamed North America during the Late Jurassic Period, around 150 million years ago.  Adults could reach lengths of more than 70 feet and weigh more than 20 tons! Because our bones were less-than-adult size, our Apatosaurus was a mere youngster. The vertebrae were also only partially fused; fusion happens as the animal grows, so the lack of complete fusion further suggested that our individual was not fully mature when it died. How old was it? We can't be completely sure, but we had fun referring to our dinosaur as the "Teenage" Apatosaurus. We are very thankful to volunteer and fossil expert Mike Marano for all of his work on the bones; he worked more than 300 hours to unearth the bones of this magnificent beast!

The specimen was part of a two-year loan from the Carnegie Museum of Natural History, Pittsburgh, PA.