Two Crested Friends at the Water

About this drawing

A pair of parasaurolophus at the pond fits what we know about these animals, since they probably liked company. They were hadrosaurs, the famous duck-billed dinosaurs, and they were common in western North America around 75 million years ago, especially in places like Utah, New Mexico and Alberta.

Their mouths were basically food processors. A toothless beak up front snipped off plants, while hundreds of teeth packed in the back formed grinding surfaces called dental batteries. When one tooth wore down, another moved in to replace it. That let them chew tough leaves and twigs better than most other dinosaurs.

Fossil sites holding many hadrosaurs together point to herd living. There's safety in numbers, after all, with more eyes watching for trouble. That mattered, because large tyrannosaurs prowled the same plains looking for a meal.

Back then a vast inland sea split North America in two, and these dinosaurs lived on the low, wet land along its shore. Rivers and swamps kept plants growing thick and green. For a long time, experts thought duck-bills spent much of their lives in the water because of those flat bills. Today, we know they were well adapted to life on land, though a drink at the water's edge surely hit the spot.

• dinosaurs
• parasaurolophus
• duck-billed dinosaurs
• cretaceous