Advertisement

Swiss Journal of Geosciences

, Volume 103, Issue 2, pp 155–162 | Cite as

Species concept in North American stegosaurs

  • Kenneth CarpenterEmail author
Article

Abstract

The plated thyreophoran or stegosaurian dinosaur Stegosaurus armatus was named in 1877 by Marsh for fragmentary remains from the Morrison Formation (Upper Jurassic) of Colorado, USA. Subsequent discoveries from the same formation in Wyoming and Colorado (USA) have been assigned to separate stegosaurian genera and species, but most of these are no longer considered valid. More recently, a partial stegosaurian skeleton from Wyoming was named Hesperosaurus mjosi. However, the validity of this genus has been questioned recently, raising the question: how much osteological difference among stegosaur taxa is needed to separate genera from species? The question is examined vis-à-vis species and genus recognition in other dinosaurs, including iguanodonts, lambeosaurine iguanodontids, chasmosaurine ceratopsians, tyrannosaurid theropods, and diplodocid sauropods. The basis for taxonomic distinction is largely philosophical: if the species are morphologically distinct enough, they should be treated as separate genera. Based on these criteria, Hesperosaurus mjosi is a distinct taxon.

Keywords

Stegosaurus Hesperosaurus Morrison Formation Late Jurassic Palaeontological species Taxonomy 

Institutional abbreviations

DMNH

Denver Museum of Natural History (now the Denver Museum of Nature & Science), Denver, CO, USA

HMNH

Hayashibara Museum of Natural History, Okayama, Japan

SMA

Sauriermuseum Aathal, Switzerland

USNM

United States National Museum (now the National Museum of Natural History, Smithsonian Institution), Washington, DC, USA

YPM

Yale Peabody Museum of Natural History, New Haven, CT, USA

Notes

Acknowledgments

First, special thanks to Peter Galton for numerous email exchanges regarding his thoughts and observations on stegosaurs. These exchanges, plus review comments, helped me formulate the revision of the manuscript. I also thank Gregory Paul for discussions over the years about dinosaur species recognition and the associated problems. We have not always agreed on whether a particular taxon should be recognized at the species or genus level, but the discussions have been fruitful nonetheless. I have borrowed freely from these discussions, and acknowledge that Greg has published more on the subject than me, most recently in his review of iguanodonts (Paul 2008). I thank him for providing the skeletal reconstructions used in the figures. I also thank Hans Jakob “Kirby” Siber for the invitation of submit a manuscript to the Symposium on Stegosauria, and for hosting my visit to the Sauriermuseum Aathal, Switzerland where several new specimens of Hesperosaurus are exhibited. Finally, thanks for Paul Upchurch for his insightful review comments, as well as those of an anonymous reviewer.

References

  1. Barrett, P. M., Butler, R. J., & Knoll, F. (2005). Small-bodied ornithischian dinosaurs from the Middle Jurassic of Sichuan, China. Journal of Vertebrate Paleontology, 25, 823–834.CrossRefGoogle Scholar
  2. Berman, D. S., & McIntosh, J. S. (1978). Skull and relationships of the Upper Jurassic sauropod Apatosaurus (Reptilia, Saurischia). Bulletin of the Carnegie Museum of Natural History, 8, 1–35.Google Scholar
  3. Brill, K., & Carpenter, K. (2007). A description of a new ornithopod from the Lytle Member of the Purgatoire Formation (Lower Cretaceous) and a reassessment of the skull of Camptosaurus. In K. Carpenter (Ed.) Horns and beaks: ceratopsian and ornithopod dinosaurs (pp. 49–67). Bloomington: Indiana University Press.Google Scholar
  4. Carpenter, K., & Currie, P. J. (1990). Introduction: on systematic and morphological variation. In: K. Carpenter, & P. J. Currie (Eds.), Dinosaur systematics: approaches and perspectives (pp. 1–8). Cambridge: Cambridge University Press.Google Scholar
  5. Carpenter, K., & Galton, P. (2001). Othniel Charles Marsh and the myth of the eight-spiked Stegosaurus. In: K. Carpenter (Ed.), The armored dinosaurs (pp. 76–102). Bloomington: Indiana University Press.Google Scholar
  6. Carpenter, K., Miles, C. A., & Cloward, K. (2001). New primitive stegosaur from the Morrison Formation, Wyoming. In: K. Carpenter (Ed.), The armored dinosaurs (pp. 55–75). Bloomington: Indiana University Press.Google Scholar
  7. Cope, E. D. (1876). Description of some new vertebrate remains from the Fort Union Beds of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia, 28, 248–261.Google Scholar
  8. Dodson, P. (1975). Taxonomic implications of relative growth in lambeosaurine hadrosaurs. Systematic Zoology, 24, 37–54.CrossRefGoogle Scholar
  9. Dodson, P. (1996). The horned dinosaurs (p. 346). Princeton: Princeton University Press.Google Scholar
  10. Dong, Z. (1973). Dinosaurs from Wuerho. Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropolopy, 11, 45–52.Google Scholar
  11. Donoghue, M. J. (1985). A critique of the biological species concept and recommendations for a phylogenetic alternative. The Bryologist, 88, 172–181.CrossRefGoogle Scholar
  12. Ereshefsky, M. (2001). The poverty of the Linnaean hierarchy: a philosophical study of biological taxonomy (328 pp). New York: Cambridge University Press.Google Scholar
  13. Farke, A. A. (2007). Cranial osteology and phylogenetic relationships of the chasmosaurine ceratopsid Torosaurus latus. In: K. Carpenter (Ed.), Horns and beaks: ceratopsian and ornithopod Dinosaurs (pp. 235–257). Bloomington: Indiana University Press.Google Scholar
  14. Galton, P. M. (2010). Species of plated dinosaur Stegosaurus (Morrison Formation, Late Jurassic) of western USA: new type species designation needed. Swiss Journal of Geosciences, 103. doi: 10.1007/s00015-010-0022-4.
  15. Hayashi, S., Carpenter, K., & Suzuki, D. (2009). Differential growth patterns between the skeleton and osteoderms of Stegosaurus (Ornithischia: Thyreophora). Journal of Vertebrate Paleontology, 29, 123–131.CrossRefGoogle Scholar
  16. Leidy, J. (1856). Notices of the remains of extinct reptiles and fishes, discovered by Dr F.V. Hayden in the badlands of the Judith River, Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia, 8, 72–73.Google Scholar
  17. Leidy, J. (1859). Extinct vertebrata from the Judith River and Great Lignite Formations of Nebraska. American Philosophical Society Transactions, 11, 139–154.CrossRefGoogle Scholar
  18. Linnaeus, C. (1735). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Nederlands, 11 pp.Google Scholar
  19. Maidment, S. C. R., Norman, D. B., Barrett, P. M., & Upchurch, P. (2008). Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia). Journal of Systematic Palaeontology, 6, 367–407.CrossRefGoogle Scholar
  20. Mantell, G. (1825). Notice on the Iguanodon, a newly discovered fossil reptile, from the Sandstone of Tilgate Forest, in Sussex. Philosophical Transactions of the Royal Society of London, 115, 179–186.CrossRefGoogle Scholar
  21. Marsh, O. C. (1877). New order of extinct Reptilia (Stegosauria) from the Jurassic of the Rocky Mountains. American Journal of Science, 114, 513–514.Google Scholar
  22. Marsh, O. C. (1889). Notice of new American dinosaurs. American Journal of Science, 137, 334–336.Google Scholar
  23. Marsh, O. C. (1894). The typical Ornithopoda of the American Jurassic. American Journal of Science, 148, 85–90.Google Scholar
  24. Mateus, O., Maidment, S. C. R., & Christiansen, N. A. (2009). A new long-necked ‘sauropod-mimic’ stegosaur and the evolution of the plated dinosaurs. Proceedings of the Royal Society, B, 276, 1815–1821.CrossRefGoogle Scholar
  25. Osborn, H. F. (1931). Cope: Master Naturalist (740 pp). Princeton: Princeton University Press.Google Scholar
  26. Paul, G. S. (2007). Turning the old into the new: a separate genus for the gracile iguanodont from the Wealden of England. In K. Carpenter (Ed.), Horns and beaks: ceratopsian and ornithopod Dinosaurs (pp. 69–77). Bloomington: Indiana University Press.Google Scholar
  27. Paul, G. S. (2008). A revised taxonomy of the iguanodont dinosaur genera and species. Cretaceous Research, 29, 192–216.Google Scholar
  28. Raup, D. M., & Stanley, S. M. (1978). Principles of paleontology (481 pp). San Francisco: W. H. Freeman & Co.Google Scholar
  29. Sampson, S. D., Ryan, M. J., & Tanke, D. H. (2008). Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Geratopsidae): taxonomic and behavioral implications. Zoological Journal of the Linnean Society, 121, 293–337.CrossRefGoogle Scholar
  30. Siber, H.J., & Möckli, U. (2009). The Stegosaurs of the Sauriermuseum Aathal. Aathal, 56 pp.Google Scholar
  31. Turner, C. E., & Peterson, F. (1999). Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, USA. In D. Gillette (Ed.) Vertebrate Paleontology in Utah (pp. 77–114) Utah: Utah Geological Survey Miscellaneous Publication 99-1.Google Scholar
  32. Upchurch, P., Tomida, Y., & Barrett, P. M. (2004). A new specimen of Apatosaurus ajax (Sauropoda, Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA (pp. 1–118) Tokyo: National Science Museum, Tokyo Monographs 26.Google Scholar
  33. Wheeler, Q. D., & Meier, R. (2000). Species concepts and phylogenetic theory: a debate (256 pp). New York: Columbia University Press.Google Scholar
  34. Wilson, J. A., & Upchurch, P. (2003). A revision of Titanosaurus Lydekker (dinosauria–sauropoda), the first dinosaur genus with a ‘Gondwanan’ distribution. Journal of Systematic Palaeontology, 1, 125–160.CrossRefGoogle Scholar
  35. Yates, A. M. (2003). The species taxonomy of the sauropodomorph dinosaurs from the Lowenstein Formation (Norian, Late Triassic) of Germany. Palaeontology, 46, 317–337.CrossRefGoogle Scholar

Copyright information

© Swiss Geological Society 2010

Authors and Affiliations

  1. 1.Prehistoric MuseumUtah State University-College of Eastern UtahPriceUSA

Personalised recommendations