Elmer S. Riggs Riggs' assistant, H. William Menke, found the first known skeleton of the giant sauropod dinosaur "Brachiosaurus altithorax" from near Grand Junction, Colorado. At the end of the 1900 field season Riggs' found a specimen of "Apatosaurus" near Fruita, a few miles from the Brachiosaurus site. This specimen was excavated during the 1901 field season, and was put on display in 1908 at the Field Museum. From these specimens he named "Brachiosaurus" and Brachiosauridae, and presented evidence that "Apatosaurus" and "Brontosaurus" were the same genus of dinosaur. He also proposed that sauropods were terrestrial animals, based on their limb structure, but
The Unknown Known I know." "The Unknown Known" was screened in the main competition section at the 70th Venice International Film Festival, and premiered at the Telluride Film Festival on August 29, 2013. The documentary has an 84% approval rating on the review aggregator website Rotten Tomatoes, based on 105 reviews with an average rating of 8.2/10. The website's critical consensus reads, "Viewers hoping to see Donald Rumsfeld admit making mistakes in public office may find "The Unknown Known" frustrating – but no less fascinating." On Metacritic, the film has a weighted average score of 69 out of 100, based on 30 critics,