The latest dinosaur being mounted at the Natural History Museum in Los Angeles is a 75-foot-long sauropod named Gnatalie (pronounced Natalie). Gnatalie is a new species and the only green dinosaur fossil in the world. It will be available for public viewing in the fall at the museum’s brand-new welcome center currently under construction. Gnatalie is a long-necked, long-tailed herbivorous dinosaur related to the Brontosaurus that lived 150 million years ago in the late Jurassic Era. That makes it older than the Tyrannosaurus rex. Researchers discovered the bones in 2007 in the Badlands of Utah.