Despite rows of teeth and its crested head, Saurolophus was unable to defend itself against attack.
Saurolophus is one of the so-called duckbill dinosaurs, known as hadrosaurs. It used its toothless beak to nip off twigs, tough leaves and pine needles, which it ground up between its many rows of teeth.
Confusingly, Saurolophus is only very distantly related to the much more popular Parasaurolophus. The type species S. osborni is known from the remains of at least three individuals. Another species, S. angustirostris, is known from the Gobi desert. Some palaeontologists think it should be the same species as S. osborni, but others think it is a different genus altogether.
Name: Saurolophus, meaning ‘lizard crest’
Size: 9-12m long and about 3m high
Food: tough plants and leaves, seeds, fruit
Lived: about 80-66 million years ago in western North America and eastern Asia in the Late Cretaceous Period
About as long as a bus, Saurolophus walked on its hind legs, but supported its body on its shorter front legs when feeding. It had no claws on it toes and no way of defending itself directly against carnivorous dinosaurs. However, Saurolophus, like other hadrosaurs, probably relied on keen senses of sight, hearing and smell, as well as their legs, to get out of trouble fast.
Scientists believe that Saurolophus had a pouch of skin on its face. It blew this up like a balloon to send warning signals to the herd or to attract a mate. It may also have used this pouch to increase the noises it made, just as frogs blow out their throats when croaking.
The distinguishing feature of Saurolophus is the prominent spine that rises above the eyes and projects backwards – the uniting feature between the species of Saurolophus is the presence of the backward-pointing spike above the eye. This is formed from the nasal bones that extend backwards and may have been associated with some sound-producing mechanism. The skull is quite narrow for a hadrosaurid, especially across the snout where we would expect to see the duck-like bill. The original species was the most complete to have been found in Canada at the time (1911). The Asian species is much larger.