page_title: Parasaurolophus
section_title: Discovery and naming
hierarchical_section_title: Parasaurolophus / Discovery and naming
caption_attribution_description: English: Incomplete Parasaurolophus walkeri type specimen in the Royal Ontario Museum. Español: El especímen tipo de Parasaurolophus walkeri en el Museo Real de Ontario. Magyar: A Parasaurolophus walkeri típuspéldányának hiányos csontváza a Royal Ontario Múzeumban.
context_page_description: Parasaurolophus is a genus of herbivorous ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, about 76.5–73 million years ago. It was an herbivore that walked both as a biped and as a quadruped. Three species are universally recognized: P. walkeri, P. tubicen, and the short-crested P. cyrtocristatus. Additionally, a fourth species, P. jiayensis, has been proposed, although it is more commonly placed in the separate genus Charonosaurus. Remains are known from Alberta, New Mexico and Utah, and possibly Heilongjiang. 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.
context_section_description: Meaning "near crested lizard", the name Parasaurolophus is derived from the Greek para/παρα "beside" or "near", saurus/σαυρος "lizard" and lophos/λοφος "crest". It is based on ROM 768, a skull and partial skeleton missing most of the tail and the hind legs below the knees, which was found by a field party from the University of Toronto in 1920 near Sand Creek along the Red Deer River in Alberta, Canada. These rocks are now known as the Campanian-age Upper Cretaceous Dinosaur Park Formation. William Parks named the specimen P. walkeri in honor of Sir Byron Edmund Walker, Chairman of the Board of Trustees of the Royal Ontario Museum. Parasaurolophus remains are rare in Alberta, with only one other partial skull from (probably) the Dinosaur Park Formation, and three Dinosaur Park specimens lacking skulls, possibly belonging to the genus. In some faunal lists, there is a mention of possible P. walkeri material in the Hell Creek Formation of Montana, a rock unit of late Maastrichtian age. This occurrence is not noted by Sullivan and Williamson in their 1999 review of the genus, and has not been further elaborated upon elsewhere.
  In 1921, Charles H. Sternberg recovered a partial skull (PMU.R1250) from what is now known as the slightly younger Kirtland Formation in San Juan County, New Mexico. This specimen was sent to Uppsala, Sweden, where Carl Wiman described it as a second species, P. tubicen, in 1931. The specific epithet is derived from the Latin tǔbǐcěn "trumpeter". A second, nearly complete P. tubicen skull (NMMNH P-25100) was found in New Mexico in 1995. Using computed tomography of this skull, Robert Sullivan and Thomas Williamson gave the genus a monographic treatment in 1999, covering aspects of its anatomy and taxonomy, and the functions of its crest. Williamson later published an independent review of the remains, disagreeing with the taxonomic conclusions.
  John Ostrom described another good specimen (FMNH P27393) from New Mexico as P. cyrtocristatus in 1961. It includes a partial skull with a short, rounded crest, and much of the postcranial skeleton except for the feet, neck, and parts of the tail. Its specific name is derived from the Latin curtus "shortened" and  cristatus "crested". The specimen was found in either the top of the Fruitland Formation or, more likely, the base of the overlying Kirtland Formation. The range of this species was expanded in 1979, when David B. Weishampel and James A. Jensen described a partial skull with a similar crest (BYU 2467) from the Campanian-age Kaiparowits Formation of Garfield County, Utah. Since then, another skull has been found in Utah with the short/round P. cyrtocristatus crest morphology.
caption: Holotype specimen of P. walkeri, showing the pathologic v-shaped notch
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