Parasaurolophus (/ˌpærəsɔːˈrɒləfəs/ PARR-ə-saw-ROL-ə-fəs or /ˌpærəˌsɔːrəˈloʊfəs/ PARR-ə- SAWR-ə-LOH-fəs; meaning "near crested lizard" in reference to Saurolophus) is a genus of ornithopod dinosaur that lived in what is now North America during the Late Cretaceous Period, about 76.5–73 million years ago. It was a herbivore that walked both as a biped and a quadruped. Three species are recognized: P. walkeri (the type species), P. tubicen, and the short-crested P. cyrtocristatus. Remains are known from Alberta (Canada), and New Mexico and Utah (United States). The genus was first described in 1922 by William Parks from a skull and partial skeleton found in Alberta.
Parasaurolophus was a hadrosaurid, part of a diverse family of Cretaceous dinosaurs known for their range of bizarre head adornments. This genus is known for its large, elaborate cranial crest, which at its largest forms a long curved tube projecting upwards and back from the skull. Charonosaurus from China, which may have been its closest relative, had a similar skull and potentially a similar crest. The crest has been much discussed by scientists; the consensus is that major functions included visual recognition of both species and sex, acoustic resonance, and thermoregulation. It is one of the rarer hadrosaurids, known from only a handful of good specimens. (see more...)