Journeying back through time, Dinosaur Days acquaints readers with eight creatures of the Mesozoic era. Using age-appropriate language, this new series will whet young paleontologists'' appetites as it uncovers when and where important fossils have been found as well as what these fossilized remains have revealed about the dinosaur''s lifestyle, including how its physical features aided survival in its prehistoric habitat and theories about its extinction. A timeline spotlights the period when the dinosaur lived, and a closing comparative graphic provides additional context on the animal''s size. Supports the Next Generation Science Standards. This introductory exploration uncovers the discovery of Apatosaurus fossils before revealing information about its era, features, and lifestyle, as well as its eventual extinction.