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 Lost World: Jurassic Park since the release of the first film, Spielberg noted that "the artistry of the creative computer people" had advanced: "There's better detail, much better lighting, better muscle tone and movement in the animals. When a dinosaur transfers weight from his left side to his right, the whole movement of fat and sinew is smoother, more physiologically correct." Winston said, "I wanted to show the world what they didn't see in 'Jurassic Park': more dinosaurs and more dinosaur action. 'More, bigger, better' was our motto." Some of the animatronics cost $1 million and weighed nine and a half tons. Michael Lantieri,