CHAPTER ONE DINOSAUR WORLD A massive Spinosaurus floats along an ancient river The 50 foot 15 m creature resembles a giant crocodile with a large sail on its back As it stalks its prey through the water the sail rises six feet 1 8 m above the surface A fish tries to dart away from the dinosaur The Spinosaurus uses its paddle like feet to lunge forward The fish disappears into the dinosaur's wide snout Spinosaurus is the largest known meat dinosaur eating
Based on its body proportions scientists believe Spinosaurus lived in the water It may sound as if this is a scene from a movie But Spinosaurus was real It is the earliest known swimming dinosaur and it lived in the waters of northern Africa 97 million years ago How do we know these things No person has ever seen a Spinosaurus in real life But these
creatures left behind bones eggs and footprints Some of these things formed into fossils A fossil by itself looks like a funny-shaped rock But fossils contain secrets To reveal those secrets we use science Scientists can discover which animal formed a fossil and how that animal lived Science provides a window into the past It allows us to learn about animals that died tens of millions of years ago Dinosaur science is part of a discipline called IN THE REAL WORLD A Fossil Birthday Cake As layers of dirt sand and debris collect on the ground the old ground gets covered up Over millions of years heat and pressure turn the old ground into rock Sometimes animals or plants that died and fell to the ground also get covered up and become fossils The rocks and fossils form a stack of layers called strata At the Blue Nile Gorge site in Ethiopia the Nile River cut through these strata like someone slicing into a birthday cake Scientists have found fish scales pieces of turtle shells and dinosaur teeth The layer a fossil comes from reveals the time period in which that animal lived and died 7
