We can dish the real dirt about dinosaurs, thanks to fossils – traces of theses astonishing animals.
Dinosaurs did not print newspapers. They did not take family snapshots or videos 65 million years ago. The only proof scientists have of dinosaurs is their fossils, especially bones. They would never have survived billions of years waiting for some human to trip over them. Luckily for paleontologists (scientists who study the past), now and then dinosaurs died, and their bones were covered by mud, or sand. As the bones sat protected from weather, they absorbed minerals from the soil around them. The minerals chemically worked their way into the bones. Millions of years later, we can find them and dig them up.
Humans were not around to see what actually killed the ancient dinosaurs. Many scientists think a meteorite, or lots of meteorites, crashed into the Earth. When the space rocks hit the ground, they made big craters and kicked up a lot of dust and dirt. If enough dust flew into the air, sunlight couldn’t get to Earth, and the plants died off. Without plants for food and oxygen, the dinosaurs died. The meteorite impact is just a theory, but a very, very good one. We may never be sure what really happened because, as this episode of Bill Nye the Science Guy points out: dinosaurs and humans did not live at the same time!
The Big Ideas
- We know dinosaurs once lived, because we've found their fossils.
- Dinosaurs lived long before people.
Did You Know That?
- Dinosaurs were not the biggest animals ever to live on Earth — blue whales are even bigger?
- The smallest known dinosaur was the Compsognathus? This dino was about the size of a chicken and weighed around 7 kilograms (15 pounds).
- The biggest dinosaur was the Brachiosaurus? They weighed about 32,500 kilograms (32 1/2 tons) and measured 22 meters (73feet) long and 14 meters (46 feet) high.
Books of Science!
- “The X-Ray Book of Dinosaurs” by Kathryn Severin. Published by Franklin Watts, 1994.
- “Dinosaurs: Strange and Wonderful” by Lawrence Pringle. Published by St. Martin’s Press, 1995.
- “Inside Dinosaurs” by Ted Dewan. Published by Doubleday, 1993.