Diplodocus now common scientific opinion that "Seismosaurus hallorum" is a species of "Diplodocus". This genus of dinosaurs lived in what is now mid-western North America at the end of the Jurassic period. "Diplodocus" is one of the more common dinosaur fossils found in the middle to upper Morrison Formation, between about 154 and 152 million years ago, during the late Kimmeridgian age. The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs, such as "Apatosaurus", "Barosaurus", "Brachiosaurus", "Brontosaurus", and "Camarasaurus". "Diplodocus" is among the most easily identifiable dinosaurs, with its typical sauropod shape, long neck and tail, and
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,