The Arizona Museum of Natural History is the premier natural history museum in Arizona. It is dedicated to inspire wonder, respect and understanding for the natural and cultural history of the Southwest. Explore Arizona and the Southwest from the creation of the earth 4.5 billion years ago to the present. See the origins of life on earth, meteorites and minerals. In Dinosaur Hall, discover some of the biggest dinosaurs that ever lived, and on Dinosaur Mountain see how some appeared and sounded in a natural context. In a Walk through Time, explore ancient Arizona’s Paleozoic Seas, Triassic Petrified Forest, monsters of the Cretaceous Seas, and the first animals to fly. “Rulers of the Prehistoric Skies”, presents the amazing diversity of Pterosaurs, the flying reptiles of the Mesozoic. Neither dinosaurs nor birds, Pterosaurs ruled the skies from about 225 to 65 million years ago.