Open Paleo

Prosaurolophus

Brown, 1916 PROH-saw-ROL-o-fus /ˌproʊsɔːˈrɒləfəs/

From Greek pro (before) and the genus name Saurolophus (crested lizard); meaning "before Saurolophus", referring to it being an earlier dinosaur with a similar head crest.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Prosaurolophus is a genus of hadrosaurid (or duck-billed) dinosaur from the Late Cretaceous of North America. It is known from the remains of at least 25 individuals, including skulls and skeletons, but this remains obscure. Its fossils have been found in the late Campanian-aged Dinosaur Park Formation in Alberta, and the roughly contemporaneous Two Medicine Formation in Montana, dating to around 75.7 to 74.1 million years ago. Its most recognizable feature is a small solid crest formed by the nasal bones, sticking up in front of the eyes.

Diagnosis

  1. Skull large, high, and elongate
  2. Incipient crest short, erect, directly above the eye, formed by prefrontals, frontals and nasals
  3. Frontals excluded from the border of the orbit
  4. Beak long and spatulate
  5. Crest comparatively low, short anteroposteriorly, slightly curved forward at apex
  6. Crest derived from anterior lateral border of frontals, supported by prefrontals and nasals

Species

Prosaurolophus maximus Brown, 1916

Type species

From Latin 'maximus' meaning 'greatest' or 'largest', referring to the large size of the type specimen.

Holotype
AMNH 5386 , American Museum of Natural History
Material
Incomplete skull and jaw. Right side weathered to mid-line, parietal crushed upward laterally, premaxillaries separated and repositioned.
Horizon
Dinosaur Park Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
North fork of Sand Creek, 12 miles below Steveville, Red Deer River, Alberta, Canada

Notable specimens

  • TMP 1998.050.0001, TMP 2016.037.0001

    Royal Tyrrell Museum of Paleontology exceptional preservation

    Two juvenile specimens preserve patches of skin from the dorsal ribs, scapular blade, and pelvic region, showing small basement scales plus larger elongate feature scales interspersed among them, a rare integument record for the genus.

    Drysdale et al. (2019)

References

  1. Drysdale, E. T.; Therrien, F.; Zelenitsky, D. K.; Weishampel, D. B.; Evans, D. C. (2019). Description of juvenile specimens of Prosaurolophus maximus (Hadrosauridae: Saurolophinae) from the Upper Cretaceous Bearpaw Formation of southern Alberta, Canada, reveals ontogenetic changes in crest morphology. Journal of Vertebrate Paleontology 38(6): e1547310. doi:10.1080/02724634.2018.1547310 drysdale2019a
  2. Brown, B. (1916). A new crested trachodont dinosaur, Prosaurolophus maximus. Bulletin of the American Museum of Natural History 35(37): 701-708. brown1916a