Parasaurolophus: The duck-billed dinosaur with a long head crest

Parasaurolophus has the most extravagant "headgear" of any duck-billed dinosaur: a long, hollow crest runs from its nostril all the way to the back of its head. It lived during the Late Cretaceous in North America and was a large plant-eater. Let's meet the dinosaur that may have "blown a horn".

Its body

The most eye-catching feature is the long, curved, backward-pointing hollow crest on top of its head, which can be more than a metre long. The crest is really a long tube inside the nasal passage. Scientists rebuilt the inside of that tube with CT scans and then simulated "blowing" it. The resulting tone was deep and long, a bit like a trombone or a low horn. Such a distinctive call may have kept the group in contact, and could also have played a part in courtship or recognition.

Inside its mouth, hundreds of teeth stood in rows, forming what is called a "dental battery". As old teeth wore down, new ones kept replacing them, letting the animal grind tough plants. Its body was strong: it usually walked on four legs, but when danger appeared it could sprint on its two hind legs.

Where it lived and what it ate

Parasaurolophus was a plant-eater, feeding on conifers, ferns and shrubs. It probably lived near water in groups, using its crest and voice to talk to its companions. It shared Late Cretaceous North America with many other hadrosaurs, horned dinosaurs and meat-eaters.

Where its fossils were found

Its fossils come mainly from western North America, especially the United States and Canada. Because of its unusual crest, it is one of the easiest hadrosaurs to recognise and an important subject for scientists studying dinosaur vocal behaviour.

What the fossils tell us — and what they do not

The skeleton and the shape of the crest tell us about the head proportions and the rough path of the nasal airway, but exactly what sound it made and how it called are mainly simulation and inference. The colour of the crest and the pattern on its skin are likewise evidence-informed reconstructions.

A note for grown-ups

You could talk with a child about where sound comes from: if you blow across a tube, what does it sound like? Parasaurolophus's long crest may have been its natural "horn". Linking a fossil to something a child can try is a great way to spark interest.