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The Parasaurolophus was about 30 feet (9 meters) long and weighed 4 tons.

Lophorhothon  The Lophorhothon (crested nose) was first found in Alabama and classified as a hadrosaur.  Scientists are now having second thoughts about which group it belongs to.  Some think it might be related to the Iguanodon.

The Corythosaurus weighed 5 tons and measured 30 feet (9 meters) in length. While some scientists were investigating its giant crest, they discovered that it makes an enormous sound when air passes through it. They think the sound was used to communicate danger and to try and woo a possible mate.

Which of these two dinosaurs do you think is a hadrosaur? In the box above your choice, write the word hadrosaur. Explain your answer on the next page.

Hadrosaurs As you have learned, some animals live in herds. Why do you think they live in such large groups? What advantages are there for living in herds? What are the disadvantages? This herd of Maisaura are walking along a river’s edge. A herd contains members of all ages and genders.