Desert Discovery T e man agreed to take Ibrahim to his dig site. Soon, Ibrahim and the man were driving across the hot, dusty desert. T en they set out on foot. T ey climbed a steep hill. “T ere,” the man said, pointing to a cave. Ibrahim climbed into the cave. Using
special tools, he gently picked at sand and rock. Within minutes, he discovered several bones. At last, he’d found where a Spinosaurus had died! Now, he’d learn more about this odd dinosaur and its life in a predator’s paradise.
Building the Beast First, Ibrahim built the dinosaur’s skeleton. Working with a team of scientists, he started with the bones found in Morocco. T ey came from the most complete skeleton of a single Spinosaurus ever found. He added Spinosaurus bones found at other sites in the Sahara. T e skeleton still wasn’t complete. Next, he looked at the German scientist’s
sketches and photos to make models of some of the missing bones. He studied relatives of the dinosaur to figure out more bones. Finally, he had his skeleton. It surprised him. It looked diff erent from any dinosaur he’d ever seen. It was 15 m long, bigger than T. rex. It had
a long, narrow head like a crocodile, with nostrils halfway up its skull. It had teeth like a crocodile, too, perfect for catching slippery fish. It had dense bones like ones a sea cow uses to control its buoyancy in water. Its flat back feet reminded Ibrahim of paddles, or webbed feet. Finally, its tail vertebrae looked a lot like those in a flexible fish’s tail. Ibrahim thought about the clues in the
bones. He thought about the similarities between Spinosaurus and animals living today. He thought about the ancient river ecosystem where Spinosaurus lived.
14 NATIONAL GEOGRAPHIC SCIENCE EXPLORER
Ruling the River To Ibrahim, the clues all pointed to one conclusion. Spinosaurus didn’t spend most of its time on land. It lived mostly in the water. It’s the first known semi-aquatic dinosaur. T is conclusion helps answer how so
many predators could have lived in one place. T is giant predator didn’t compete with land predators for food. Instead, it had its own niche in this ecosystem. It ruled the rivers. With high nostrils, it could paddle through
the water mostly submerged and still breathe. With its massive size, it could prey on the biggest fish and turtles, finding plenty to eat. Some mysteries remain, though. One
involves the giant sail. Some scientists think it controlled the dinosaur’s body temperature. As blood circulated through the sail, it could release or trap heat in the body, they say. So far, there’s little evidence to prove
this. In fact, the bones are thin and have few channels for blood vessels. Instead, Ibrahim thinks Spinosaurus may have used its sail as a warning. It could have stuck out of the water as Spinosaurus hunted. Ibrahim continues to dig to find answers
to his Spinosaurus questions. For now, one thing appears clear. T e more impossible the questions seem, the more determined Ibrahim is to find the answers.
apex predator: the top predator in an ecosystem
ecosystem: the interaction of living and nonliving things in an environment
fossil record: the information about Earth’s past that comes from studying fossils
niche: a specialized place or role within an ecosystem
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