Some 60 million years have passed since the dinosaurs ruled the world. In that time mountains have risen, wasted away, and risen again. Glaciers have come and gone. Many species of plants and animals evolved and passed on to extinction. Every life form meets the test—adapt or die. That test is as real to the dusty lizard basking on the quarry face as it was to the dinosaurs whose bones you came to see. Key to Pronunciation Dinosauria (dy-noh-SAWR-eea) Antrodemus (an-troh-DEE-mus) Apatosaurus (apato-SAWR-us) Ankylosaurus (an-KEELOH-sawr-us) Camptosaurus (camp-toh-SAWR-us) Stegosaurus (steg-oh-SAWR-us) Triceratops (try-SER-a-tops) Archosauria (Ark-oh-SAWR-eea) Mesozoic (MEZ-oh-zoh-ic) Triassic (try-ASS-ic) Jurassic (jur-ASS-ic) Cretaceous (kre-TAY-shus) Tyrannosaurus (ty-ran-oh-SARH-us) Saurischia (sawr-ISS-key-a) Ornithischia (orni-THISS-key-a) Diplodocus (di-PLOD-icus) Camarasaurus (camara-SAWR-us) Protiguanodon (pro-teeg-GUAN-oh-don) Suggested Readings Andrews, Roy Chapman. _All About Dinosaurs_, 146 pp. Random House, New York. A very interesting book about dinosaurs and the men who study them. Children, 9-12 years old. Colbert, Edward H. _Evolution of the Vertebrates_, 479 pp. John Wiley and Sons, Inc., New York. 1955. A very readable account of vertebrate evolution for the student or serious amateur. —— ——. _Dinosaurs_, 4th ed., 32 pp. American Museum of Natural History, New York. 1957. A good brief treatment of all dinosaurs. Excellent illustrations. Dunbar, Carl O. _Historical Geology_, 567 pp. Wiley, New York. 1949. An excellent treatment of earth’s history and life from the beginning to the present. Life Editorial Staff. _The World We Live In_, 304 pp. Simon & Schuster, New York. 1955. Elaborately illustrated book about the world’s natural history. Transcriber’s Notes —Retained publication information from the printed edition: this eBook is public-domain in the country of publication. —In the text versions only, text in italics is delimited by _underscores_. End of the Project Gutenberg EBook of Dinosaur National Monument, Colorado-Utah, by John M. Good and Theodore E. White and Gilbert F. Stucker