page_title: Kritosaurus
section_title: Formerly assigned species and material
hierarchical_section_title: Kritosaurus / History of discovery / Formerly assigned species and material
caption_attribution_description: DSC06530
context_page_description: Kritosaurus is an incompletely known genus of hadrosaurid dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard", but is often mistranslated as "noble lizard" in reference to the presumed "Roman nose".
context_section_description: In 1984, Argentine paleontologist José Bonaparte and colleagues named Kritosaurus australis for hadrosaur bones from the late Campanian-early Maastrichtian Los Alamitos Formation of Rio Negro, Patagonia, Argentina. This species is now thought to be a synonym of Secernosaurus koerneri.
  In 1990, Jack Horner and David B. Weishampel once again separated Gryposaurus, citing the uncertainty associated with the latter's partial skull. Horner in 1992 described two more skulls from New Mexico that he claimed belonged to Kritosaurus and showed that it was quite different from Gryposaurus, but the following year Adrian Hunt and Spencer G. Lucas put each skull in its own genus, creating Anasazisaurus and Naashoibitosaurus.
  Adrian Hunt and Spencer G. Lucas, American paleontologists, named Anasazisaurus horneri in 1993. The name was derived from the Anasazi, an ancient Native American people, and the Greek word sauros ("lizard"). The Anasazi were famous for their cliff-dwellings, such as those in Chaco Canyon, near the location of fossil Anasazisaurus remains. The term "Anasazi" itself is actually a Navajo language word, anaasází ("enemy ancestors"). The species was named in honor of Jack Horner, the American paleontologist who first described the skull in 1992. The holotype skull (and only known specimen) was collected in the late 1970s by a Brigham Young University field party working in San Juan County, and is housed at BYU as BYU 12950.
   
  Horner originally assigned the Anasazisaurus skull to Kritosaurus navajovius, but Hunt and Lucas could not find any diagnostic features in the limited material of Kritosaurus and judged the genus to be a nomen dubium. Since the Anasazisaurus skull did have diagnostic features of its own, and did not appear to them to share any unique features with Kritosaurus, it was given the new name Anasazisaurus horneri, an opinion which was supported by some later authors. Not all authors have agreed with this, Thomas E. Williamson in particular defending Horner's original interpretation, and several subsequent studies recognized both distinct genera.
  A comprehensive study of known Kritosaurus material published by Albert Prieto-Márquez in 2013 upheld the status of Naashoibitosaurus as a distinct genus, but found that the type specimens of Kritosaurus and Anasazisaurus were indistinguishable when comparing overlapping elements (i.e. only those bones preserved in both specimens). Prieto-Márquez therefore regarded Anasazisaurus as a synonym of Kritosaurus, but retained it as the distinct species K. horneri.
  A partial skeleton from the Sabinas Basin in Mexico was described as Kritosaurus sp. by Jim Kirkland and colleagues, but considered an indeterminate saurolophine by Prieto-Márquez (2013). This skeleton is about 20% larger than other known specimens, around 11 meters [36 ft] long, and with a distinctively curved ischium, and represents the largest known well-documented North American saurolophine. Unfortunately, the nasal bones are also incomplete in the skull remains from this material.
caption: Unnamed specimen from the Sabinas Basin in Mexico, assigned to Kritosaurus sp. by Kirkland et al. (2006)[24] but considered an indeterminate saurolophine by Prieto-Márquez (2013).[25]
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