Dinosaurs and their extinction

  The Pachycephalosaurus  had a remarkably thick, dome-shaped skull. Researchers have debated whether these dinosaurs used their heads in combat or display behaviors. It was a bipedal herbivore or omnivore that lived in North America.

 The  Brachiosaurus was a giant plant-eater with a long neck. Its height helped it reach leaves high in trees that other dinosaurs could not access.

Velociraptor was a small, fast predator that lived in Asia. It had sharp claws, feathers, and hunted smaller animals for food.

Stegosaurus was known for the large plates on its back and spikes on its tail. It was a herbivore that ate plants and used its tail for protection.

  The Triceratops was a plant-eating dinosaur with three horns and a large frill around its head. It lived in North America and may have used its horns to defend itself from predators.

 THE BRONTOSAURUS Brontosaurus was a herbivore . It didn’t chew its food much—instead, it swallowed plants and probably used stones in its stomach (called gastroliths) to help grind them up. Brontosaurus was a sauropod , meaning it had: A very long neck and tail A small head compared to its body Thick, pillar-like legs A huge, heavy body The naming confusion: This is where things get interesting: In the late 1800s, a scientist named Othniel Charles Marsh named a dinosaur Brontosaurus (“thunder lizard”). Later, scientists decided the fossils actually belonged to another dinosaur called Apatosaurus . So “Brontosaurus” was dropped for a long time.