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Temporal range: Upper Cretaceous, 76.5 Ma
Roberta Brachylophosaurus.jpg
Fossil nicknamed Roberta
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Dinosauria
Order: Ornithischia
Suborder: Cerapoda
Family: Hadrosauridae
Subfamily: Saurolophinae
Tribe: Brachylophosaurini
Genus: Brachylophosaurus
Sternberg, 1953
  • B. canadensis Sternberg, 1953 (type)
Scale diagram comparing relative sizes of Brachylophosaurus and humans

Brachylophosaurus was a mid-sized herbivorous dinosaur, a member of the hadrosaur family. It is known from several skeletons and bonebed material from the Judith River Formation of Montana and the Oldman Formation of Alberta.[1] They lived about 76.5 million years ago.[2]

Description[change | change source]

This animal had a bony crest, a flat, paddle-like plate over the top of the skull.[3] Some individuals had crests that covered nearly the entire skull roof, while others had shorter, narrower crests.[4][5][6] Other notable features are the unusually long forelimbs and the beak of the upper jaw being wider than other contemporary hadrosaurs.[3]

Teeth[change | change source]

Otherwise, Brachylophosaurus was a typical hadrosaur. It reached an adult length of 9 meters (30 ft).[3] Like other hadrosaurs, Brachylophosaurus had cheeks to keep food in the mouth while it chewed with its hundreds of close-fitting teeth.[3] These teeth could be used to chew efficiently,[3] a feature rare among reptiles, but common among ornithischia like Brachylophosaurus.

Tumours[change | change source]

In 2003, evidence of tumors, including metastatic cancer, was discovered in fossilized Brachylophosaurus skeletons. Rothschild and co-workers tested dinosaur vertebrae for tumors using computerized tomography and fluoroscope screening. Several other hadrosaurs, including Edmontosaurus, Gilmoreosaurus, and Bactrosaurus, also tested positive. Although more than 10,000 fossils were examined in this manner, the tumors were limited to Brachylophosaurus and closely related genera. The reason for this is not known.[7]

Complete dinosaur fossils[change | change source]

In 1994, amateur paleontologist Nate Murphy discovered an immaculate, complete and uncrushed brachylophosaur skeleton which he nicknamed "Elvis".[8] More impressive finds lay ahead for Murphy and his team from the Judith River Dinosaur Institute. In 2000, "Leonardo", a fully articulated and partially mummified skeleton of a young adult brachylophosaur, was discovered.[9][10] It is considered one of the most spectacular dinosaur finds ever, and was included in the Guinness Book of World Records.[11] They subsequently excavated "Roberta", an almost complete slender skeleton, and "Peanut", a partially preserved juvenile with some skin impressions.

References[change | change source]

  1. Horner, John R. (2004). "Hadrosauridae". In Weishampel, David B.; Osmólska, Halszka; and Dodson, Peter (eds). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 438–463. ISBN 0-520-24209-2.  Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. Arbour, V. M.; Burns M.E.; and Sissons R.L. (2009). "A redescription of the ankylosaurid dinosaur Dyoplosaurus acutosquameus Parks, 1924 (Ornithischia: Ankylosauria) and a revision of the genus". Journal of Vertebrate Paleontology 29 (4): 1117–1135. doi:10.1671/039.029.0405. 
  3. 3.0 3.1 3.2 3.3 3.4 Brachylophosaurus. In: Dodson, Peter et al The Age of Dinosaurs. Publications International. p. 134. ISBN 0-7853-0443-6
  4. Prieto-Marquez, Alberto (2005). "New information on the cranium of Brachylophosaurus, with a revision of its phylogenetic position". Journal of Vertebrate Paleontology 25 (1): 144–156. doi:10.1671/0272-4634(2005)025[0144:NIOTCO]2.0.CO;2. 
  5. Hopson, James A. (1975). "The evolution of cranial display structures in hadrosaurian dinosaurs". Paleobiology 1 (1): 21–43. 
  6. Weishampel, David B. (1990). "Hadrosauridae". In Weishampel, David B.; Osmólska, Halszka; and Dodson, Peter (eds). The Dinosauria (1st ed.). Berkeley: University of California Press. pp. 534–561. ISBN 0-520-06727-4.  Unknown parameter |coauthors= ignored (|author= suggested) (help)
  7. Rothschild, B.M.; Tanke, D.H., Helbling II, M. and Martin, L.D. (2003). "Epidemiologic study of tumors in dinosaurs". Naturwissenschaften 90 (11): 495–500. doi:10.1007/s00114-003-0473-9. PMID 14610645. Retrieved 2008-07-25. 
  8. "Brachylophosaurus dinosaur discovery". Judith River Dinosaur Institute. 2002. Retrieved 2008-07-13. 
  9. Murphy, Nate L. (2006). ""Leonardo," a mummified Brachylophosaurus from the Judith River Formation". In Carpenter, Kenneth (ed.). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Bloomington and Indianapolis: Indiana University Press. pp. 117–133. ISBN 0-253-34817-X.  Unknown parameter |coauthors= ignored (|author= suggested) (help)
  10. "Dear Mummy: Rare fossil reveals common dinosaur's soft tissue: Science News Online,". 2002-10-19. Archived from the original on 2007-01-14. Retrieved 2007-07-06. 
  11. "Brachylophosaurus dinosaur discovery". Judith River Dinosaur Institute. 2002. Retrieved 2008-07-13.