Dinosaurs

This passage discusses dinosaurs and how they lived.

Lexile Level: 990L

Categories: History Animals & Nature

Even though the oldest dinosaurs lived 230 million years ago, we are still studying them today. Dinosaur fossils help scientists understand what happened to the earth before any people lived here. In fact, people didn't inhabit the earth for another 65 million years after dinosaurs became extinct! About 700 species of dinosaurs have been identified. Some ate plants, lizards, turtles, and eggs. Others feasted on other dinosaurs or dead animals. Dinosaurs often were friendly toward each other, and some traveled together looking for food. Dinosaurs came in all shapes and sizes, but one of the biggest species, the brachiosaurus, was the length of two school buses and as tall as a four-story building. The smallest dinosaur, the composognathus, was just about the size of a chicken. Scientists aren't exactly sure what made the dinosaurs die out 65 million years ago, but many think a large meteorite crashed into Earth and killed many of them. Birds and turtles are thought to be ancestors of the extinct beasts.