Susan Heinrichs Gray

"Long ago, a once-mighty Allosaurus stalked the land searching for helpless prey for dinner, too sick to battle stronger dinosaurs. Millions of years later, scientists discovered the bones of this 'different lizard' in Wyoming and named him Big Al. Read how Big Al helped them learn more about Allosaurus and its days on Earth. Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for...

"Spinosaurus was a truly unique dinosaur. But it has certainly left behind plenty of questions for scientists to answer! Students will enjoy developing their own conclusions about the life and times of this spiny lizard. Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for further research, a Did-You-Know section, and an overview of the geologic time scale"--Publisher description....

"Life was often difficult for the Iguanodon. It couldn't fight larger dinosaurs with sharp teeth or pointy spikes. Even thunderstorms could pose a danger. Learn how Iguanodon survived on Earth for nearly twenty million years and why its fossils have been discovered all over the planet. Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for further research, a Did-You-Know section,...

"Find out how the enormous, plant-eating Apatosaurus gained the name 'deceptive lizard.' Learn what role it played in 'The Great Bone Wars' of the 1870s. Follow the many changing theories surrounding Apatosaurus, and come up with your own ideas about what life was like for this strange and mysterious dinosaur! Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for further research,...

"Imagine walking down the street and running into an Ankylosaurus. Its heavy, plated body and thick spines would surprise anybody! But despite its size and armor, this 'stiff lizard' could move pretty quickly when it needed to. Discover how Ankylosaurus continues to surprise scientists--and unsuspecting readers--to this day. Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for...

"The story of the Maiasaura is a story of good mothers, both dinosaur and human! One good mom's discovery of Maiasaura bones changed the ideas of many scientists about how some dinosaurs cared for their young. Find out for yourself what made Maiasaura such a good dino parent. Would you like one as your mother? Additional features to enhance comprehension include informative sidebars, a glossary of key words and phrases, sources for further research,...

Explains how electricity is created and stored, what it is made of, and how it travels through wires and outlets.

Explains what geology is, shows how the Earth itself and rocks change, and looks at how geologists study the polar regions and outer space.

Understanding motion is a key concept in the field of physics. Readers will learn about forces such as inertia and friction as they complete the exciting experiments in this book. The discoveries of scientists such as Isaac Newton and Leonardo da Vinci are highlighted to illustrate how our understanding of motion has changed over time.