A carnivore that was longer and heavier than the iconic T. rex—the Spinosaurus was the biggest meat-eating dinosaur and moved on two legs during the late Cretaceous period. Readers learn that the Spinosaurus spent a lot of time in water, and notably had a large sail on its back that could grow to 7 feet (2.1 m) high! Age-appropriate images and infographics accompany the many fun facts readers learn throughout the guide, and they can even discover the fossils of the animal as well as weather conditions during its time on Earth.