Dinosaurs A to Z
Hadrosauridae

Parasaurolophus walkeri PAR-uh-saw-ROL-oh-fus

"Near-crested lizard"

Parasaurolophus silhouette
You 1.8 m (5.9 ft) tall
Parasaurolophus 10 m (33 ft) long
as long as 6 people standing fingertip to fingertip
silhouette · Scott Hartman (CC-BY) via PhyloPic
Length
10 m (33 ft) — About 10 m long, ~2.5 tonnes — known for its long backward-curving crest.
Period
Late Cretaceous (76–73 Mya)
Place
North America · Alberta, Canada · New Mexico · Utah
Food
Herbivore — Tough plants — pine needles, leaves, twigs, all ground up by dental batteries of hundreds of teeth.
Clade
Hadrosauridae Dinosauria Ornithischia Cerapoda Ornithopoda Iguanodontia Duck-billed dinosaurs with tooth batteries.

A duck-billed [[hadrosaur]] whose long, curved tube crest may have trumpeted across the Cretaceous.

Parasaurolophus reconstruction by Leandra Walters, Phil Senter, James H. Robins
Reconstruction · Leandra Walters, Phil Senter, James H. Robins (CC-BY)

Parasaurolophus had a long hollow crest growing back from the top of its head. The crest contained tubes that connected to the nasal passages, and when researchers built scale models and blew through them they produced low foghorn sounds — proof that the crest worked as a resonator. Parasaurolophus probably called to other members of its herd across long distances.

More about Parasaurolophus

Discovery

Named by William Parks · 1922 · Near Sand Creek along the Red Deer River in Alberta, in rocks now known as the Dinosaur Park Formation.

A field party from the University of Toronto found a skull and partial skeleton (ROM 768) in 1920, missing most of the tail and the back legs below the knees. Parks described and named it in 1922 as P. walkeri, the type species.

The name means "beside crested lizard" or "near crested lizard", from the Greek para ("beside" or "near"), saurus ("lizard"), and lophos ("crest"). It was named in reference to Saurolophus, which it was first thought to resemble.

William Parks. The paleontologist who first described the genus in 1922, naming the type species P. walkeri in honor of Sir Byron Edmund Walker, chairman of the Board of Trustees of the Royal Ontario Museum.

What was the long tube crest actually for?
Several functions have been proposed, including visual recognition of species and sex, acoustic resonance, and thermoregulation. The resonating-chamber idea, suggesting the crest produced low-frequency calls to alert the group, was first put forward by Wiman in 1931. No single explanation is settled.
Is Charonosaurus really a Parasaurolophus?
A proposed fourth species, P. jiayinensis, is more commonly placed in the separate genus Charonosaurus from northeastern China. Charonosaurus may be its closest relative, possibly forming the cladeA branch of the tree of life: an ancestor and all of its descendants. Parasaurolophini, but whether it belongs in the genus is unresolved.

What we know

  • Long hollow crest with internal tubes connecting to the nostrils.
  • Acoustic models show the crest could produce deep foghorn-like calls.
  • Hadrosaur — closely related to Edmontosaurus, Maiasaura, and Corythosaurus.
  • Dental battery of about a thousand teeth, used to grind tough plants.

What we guess

  • Exact call pitch and pattern — depends on soft tissue we can't reconstruct.
  • Whether males and females had different crests (sexual dimorphism is suggested but unproven).
  • How fast the young grew — likely fast, like other hadrosaurs.