Skip to main content

The evolution of cranial display structures in hadrosaurian dinosaurs

  • James A. Hopson (a1)

A theory is presented that cranial crests of hadrosaurs were visual and acoustical display organs. Facial morphology and phylogeny of the Hadrosauridae and earlier theories of crest function are reviewed. The following hypothesis is presented: cranial crests, whether hollow or solid, served as visual signal structures, and hollow lambeosaur crests were also vocal resonators; all crests promoted successful matings within species, i.e., they served as premating genetic isolating mechanisms. The following predictions are tested and found to support the hypothesis: (1) hadrosaurs had well-developed eyes and ears; (2) external features of crests varied independently of internal structure; (3) crest variations were species-specific and sexually-dimorphic; (4) crest distinctiveness correlates with species diversity; (5) crest size tended to increase through time. The circumnarial depression on the side of the face in hadrosaurines housed an inflatable diverticulum of the nasal passage which served as a visual display organ. Primitive hadrosaurs (kritosaurs) possessed a small nasal horn used as a butting weapon in intraspecific combat. Because the weapon was also used in intimidative displays, narial diverticula evolved to draw attention to it. In the kritosaur Brachylophosaurus fighting was modified to ritualized head-pushing using the flat nasal “shield”. Saurolophines expanded the diverticula on to the elongated nasal horn, converting the weapon to a dominance rank symbol. In non-crested edmontosaurs, enlarged diverticula assumed a vocalization function. Lambeosaurs created resonators by enclosing the diverticula in bone; they further enhanced the resonator function of the nose by forming elongated “organ pipes” in the premaxillae. This “pushed” the olfactory region above the eyes as a conspicuous dome which then was modified to form species-specific visual display organs.

Hide All
Abel, O. 1924. Die neuen Dinosaurierfunde in der Oberkreide Canadas. Jahrg. Naturwiss. Berlin. 12:709716.
Bakker, R. T. 1971. Dinosaur physiology and the origin of mammals. Evolution. 25:636658.
Bellairs, A. 1970. The Life of Reptiles. Universe Books, New York. 2 vols. 590 pp.
Campbell, B. (ed.) 1972. Sexual Selection and the Descent of Man, 1871–1971. Aldine. New York. 378 pp.
Colbert, E. H. 1945. The Dinosaur Book. Amer. Mus. Nat. Hist., Man and Nature Publ., no. 14, 156 pp.
Colbert, E. H. 1955. Evolution of the Vertebrates. John Wiley and Sons. New York. 479 pp.
Colbert, E. H. 1961. Dinosaurs. Their Discovery and Their World. Dutton. New York, 300 pp.
Colbert, E. H. 1965. The Age of Reptiles. Weidenfeld and Nicolson. London. 228 pp.
Davitashvili, L. Sh. 1961. Teoriya Polovogo Otbora (The theory of sexual selection). Moscow, Izdatel'stvo Akademii Nauk (Academy of Sciences Press). 538 pp.
Dodson, P. (in press). Taxonomic implications of relative growth in lambeosaurine hadrosaurs.
Eibl-Eibesfeldt, I. 1970. Ethology, the Biology of Behavior. Holt, Rinehart and Winston. New York. 530 pp.
Estes, R., and Berberian, P. 1970. Paleoecology of a later Cretaceous community from Montana. Breviora. 343:135.
Ewer, R. F. 1968. Ethology of Mammals. Plenum Press. New York. 418 pp.
Galton, P. M. 1970. Pachycephalosaurids—dinosaurian battering rams. Discovery, New Haven. 6(1):2332.
Galton, P. M. 1971. A primitive dome-headed dinosaur (Ornithischia: Pachycephalosauridae) from the Lower Cretaceous of England and the function of the dome of pachycephalosaurids. J. Paleont. 45:4047.
Geist, V. 1966. The evolution of horn-like organs. Behaviour 27:175214.
Geist, V. 1971. The relation of social evolution and dispersal in ungulates during the Pleistocene, with emphasis on the Old World deer and the genus Bison. Quaternary Res. 1:283315.
Geist, V. 1972. An ecological and behavioural explanation of mammalian characteristics and their implication to therapsid evolution. Z. Saugetierkunde. 37:115.
Gould, S. J. 1973a. The misnamed, mistreated, and misunderstood Irish elk. Natural History. 82(3):1019.
Gould, S. J. 1973b. Positive allometry of antlers in the “Irish elk”, Megaloceros giganteus. Nature 244:375376.
Gould, S. J. 1974. The origin and function of “bizarre” structures: antler size and skull size in the “Irish elk”, Megaloceros giganteus. Evolution 28:191220.
Guthrie, R. D. 1970. Bison evolution and zoogeography in North America during the Pleistocene. Quart. Rev. Biol. 45:115.
Harris, V. A. 1964. The Life of the Rainbow Lizard. Hutchinson. London. 174 pp.
Heaton, M. J. 1972. The palatal structure of some Canadian Hadrosauridae (Reptilia: Ornithischia) Can. J. Earth Sci. 9:185205.
Jenssen, T. A. 1970. Female response to filmed displays of Anolis nebulosus (Sauria, Iguanidae). Anim. Behav. 18:640647.
King, J. E. 1964. Seals of the World. Brit. Mus. (Nat. Hist.) London. 154 pp.
Kurtén, B. 1968. The Age of the Dinosaurs. World Univ. Library. McGraw-Hill. New York. 255 pp.
Kurzanov, S. M. 1972. O polovom dimorfizme prototseratopov (Sexual dimorphism in protoceratopsians). Paleont. Zhur. 1972:104112.
Langston, W. Jr. 1960. The vertebrate fauna of the Selma Formation of Alabama, Part 6: The dinosaurs. Fieldiana: Geol. Mem. 3:313361.
Lull, R. S., and Wright, N. E. 1942. Hadrosaurian dinosaurs of North America. Geol. Soc. Amer. Spec. Pap. 40:1242.
Mayr, E. 1963. Animal Species and Evolution. Harvard University Press. Cambridge. 797 pp.
Neill, W. T. 1971. The Last of the Ruling Reptiles: Alligators, Crocodiles, and Their Kin. Columbia University Press. New York. 486 pp.
Nopcsa, F. 1929. Sexual differences in ornithopodous dinosaurs. Palaeobiologica. 2:187201.
Ostrom, J. H. 1961. Cranial morphology of the hadrosaurian dinosaurs of North America. Amer. Mus. Nat. Hist. Bull. 122:37186.
Ostrom, J. H. 1962. The cranial crests of hadrosaurs. Postilla. 62:129.
Parsons, T. S. 1970. The nose and Jacobson's organ. p. 99191. In, Gans, C. and Parsons, T. S. (eds.). Biology of the Reptilia. Morphology B, Vol. 2. Academic Press. London.
Piveteau, J. 1955. Traité de Paléontologie. Vol. 6. Masson. Paris. 1113 pp.
Rand, A. S., and Williams, E. E. 1970. An estimation of redundancy and information content of anole dewlaps. Amer. Naturalist. 104:99103.
Romer, A. S. 1933. Vertebrate Paleontology. Univ. Chicago Press. Chicago. 491 pp.
Romer, A. S. 1945. Vertebrate Paleontology. (2nd ed.). Univ. Chicago Press. Chicago. 687 pp.
Russell, D. A. 1967. A census of dinosaur specimens collected in western Canada. Nat. Mus. Canada Nat. Hist. Pap. 36:113.
Russell, D. A. 1970. The dinosaurs of Central Asia. Geog. J. 81(6):208215.
Russell, D. A., and Chamney, T. P. 1967. Notes on the biostratigraphy of dinosaurian and microfossil faunas in the Edmonton Formation (Cretaceous), Alberta. Nat. Mus. Canada Nat. Hist. Pap. 35:122.
Russell, L. S. 1946. The crest of the dinosaur Parasaurolophus. Contrib. Roy. Ont. Mus. Paleont. 11:15.
Steel, R. 1969. Ornithischia. In, Kuhn, O. (ed.) Handbuch der Paläoherpetologie. Part 15. Fischer. Stuttgart. 84 pp.
Sternberg, C. M. 1935. Hooded hadrosaurs of the Belly River series of the upper Cretaceous: a comparison, with descriptions of new species. Nat. Mus. Canada, Bull. 77(52):137.
Sternberg, C. M. 1939. Were there proboscisbearing dinosaurs? Discussion of cranial protuberances in the Hadrosauridae. Ann. Mag. Nat. Hist. Ser. 2, 3:556560.
Sternberg, C. M. 1942. New restoration of a hooded duck-billed dinosaur. J. Paleontol. 16:133134.
Sternberg, C. M. 1953. A new hadrosaur from the Oldman Formation of Alberta: discussion of nomenclature. Nat. Mus. Canada, Bull. 128:275286.
Sternberg, C. M. 1954. Classification of American duck-billed dinosaurs. J. Paleontol. 28:382383.
Sternberg, C. M. 1964. Function of the elongated narial tubes in the hooded hadrosaurs. J. Paleontol. 38:10031004.
Trivers, R. L. 1972. Parental investment and sexual selection. p. 136179. In, Campbell, B. G. (ed.). Sexual Selection and the Descent of Man, 1871–1971. Aldine Press. New York.
Underwood, G. 1970. The eye. p. 197. In, Gans, C. and Parsons, T. S. (eds.). Biology of the Reptilia. Morphology B, Vol. 2. Academic Press. London.
Versluys, J. 1936. Kranium und Visceralskelett der Sauropsiden. 1. Reptilien. pp. 699808. In, Bolk, , et al., eds. Handbuch der vergleichenden Anatomie der Wirbeltiere. Vol. 4. Urban and Schwarzenberg, Berlin.
Walther, F. 1958. Zum Kampf-und Paarungsverhalten einiger Antilopen. Zs. Tierpsychol. 15:340380.
Wilfarth, M. 1938. Gab es rüsseltragende Dinosaurier? Zeitschr. Deutsche Geol. Gesell. 90:87100.
Wilfarth, M. 1939. Die Nasenbasis der Lambeosaurinae. Zentralbl. Min. Geol. Palaeont. Ser. B, 2439.
Wilfarth, M. 1940. Der Atemrüssel der Hadrosauriden. Halle. 124.
Wilfarth, M. 1947. Rüsseltragende Dinosaurier. Orion 2:525532.
Wiman, C. 1931. Parasaurolophus tubicen, n. sp. aus der Kreide in New Mexico. Nova Acta R. Soc. Sci. Upsaliensis. Ser. 4, 7(5):111.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0094-8373
  • EISSN: 1938-5331
  • URL: /core/journals/paleobiology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed