As much as two hundred and fifty-three million years ago, the most incredible beasts roamed this earth. They ruled supreme on the land, under the water, and in the air for some one hundred million years before their time came to an end. Now, all these years later, we study their bones--and the earth's memory of their bones--to learn as much about them as we can. For years, humans have marveled at dinosaurs and have strived to learn more about these great beasts. The Secrets of Dinosaurs, the first volume from the PNSO Children's Encyclopedia, is a valuable book for anyone who shares this fascination! With beautifully detailed illustrations and thorough information on nearly one hundred species spanning three geological periods, you can immerse yourself in their world and learn all the secrets of dinosaurs!