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Stephanosaurus

Lambe, 1914 Nomen dubium

From Greek 'stephanos' ('crown') and 'sauros' ('lizard'), for the crested skull Lambe referred to the species.

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

Stephanosaurus is a dubious genus of hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Lambe (1914) proposed it for the species Lambe had described in 1902 as Trachodon marginatus, and referred a crested skull to it. That skull was later shown to belong to a different animal, and the type material of the species cannot be diagnosed, so the name is treated as a nomen dubium and the modern literature discusses the taxon under its original combination.

Species

Stephanosaurus marginatus Lambe, 1914 Nomen dubium

Type species

Holotype
NMC 419 , Canadian Museum of Nature
Material
Left humerus, ulna and radius, a pedal metatarsal and phalanges, cervical zygapophyses, ribs, tooth fragments, ossified tendons and impressions of the integument.
Notes
Lambe (1914) cited a lower jaw ramus and a maxilla as the type, but Gilmore (1924) showed from the 1902 description that the type is the associated individual, and that the maxilla and dentary came from two different animals collected three weeks apart. The fore limb has the humerus longer than the radius, the proportion of the non-crested hadrosaurs, so it cannot belong with the crested skull Lambe referred to the species. The specimen is also cited as GSC 419.
Horizon
Belly River Group, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Red Deer River district, Alberta, Canada None of the works cited assigns the type to one of the three formations the Belly River series was later split into, and the material was collected across a long stretch of river rather than at a recorded site. Lambe (1902) does note that in the Red Deer River district the upper beds of the series are represented, with probably the upper part of the lower beds, which leans toward the upper part of the group without settling it.

References

  1. Lambe, L. M. (1914). On a new genus and species of carnivorous dinosaur from the Belly River Formation of Alberta, with a description of the skull of Stephanosaurus marginatus from the same horizon. The Ottawa Naturalist 28: 13-20.

    Proposes the genus for the species described in 1902 as Trachodon marginatus, and refers a crested skull to it.

    lambe1914a
  2. Parks, W. A. (1923). Corythosaurus intermedius, a new species of trachodont dinosaur. University of Toronto Studies, Geology Series 15: 1-57.

    Holds that the name can apply only to the original type material, and erects Lambeosaurus lambei for the referred crested skulls.

    parks1923a
  3. Gilmore, C. W. (1924). On the genus Stephanosaurus, with a description of the type specimen of Lambeosaurus lambei Parks. National Museum of Canada Bulletin 38(43): 29-48.

    Re-examines the type, shows the referred maxilla and dentary come from different individuals, and treats the genus as a junior synonym of Kritosaurus on priority.

    gilmore1924b
  4. White, T. E. (1973). Catalogue of the genera of dinosaurs. Annals of Carnegie Museum 44: 117-155. doi:10.5962/p.243870

    Gives the type as NMC 419, limb bones with fragments of vertebrae, ribs and teeth from the Belly River of the Red Deer River.

    white1973a
  5. Brett-Surman, M. K. (1989). A revision of the Hadrosauridae (Reptilia: Ornithischia) and their evolution during the Campanian and Maastrichtian. 1-272. Doctoral thesis, The George Washington University.

    Records the type species as generically indeterminate.

    brett-surman1989a
  6. Horner, J. R.; Weishampel, D. B.; Forster, C. A. (2004). Hadrosauridae. The Dinosauria, Second Edition (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 438-463. University of California Press, Berkeley.

    Lists the species among hadrosaurid nomina dubia under its original combination.

    horner2004a
  7. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Records that the skull fragments included in the description were later found to come from different animals.

    jones2026a
  8. Lambe, L. M. (1902). New genera and species from the Belly River Series (mid-Cretaceous). Geological Survey of Canada Contributions to Canadian Palaeontology 3(2): 25-81. doi:10.5281/zenodo.3233762

    Reports that the Red Deer River district exposes the upper beds of the Belly River series, with probably the upper part of the lower beds.

    lambe1902a