A femur from a Camarasaurus dinosaur is covered with plaster and burlap in preparation for its removal from the site. Next to the femur are a pile of odd bones from other dinosaurs that also died in the same swamp. These piles of bones make identification of one particular species very difficult. This fossil is from the Jurassic-age Morrison formation in Wyoming. Camarasaurus was a long-necked, long-tailed giant herbivore, measuring about 24 to 65 feet long and weighing up to 20 tons.