Mikko's Phylogeny Archive

†Pachycephalosauria – thick-headed dinosaurs

After Sereno, 2000, and Williamson & Carr, 2002

Alternative phylogeny after Sullivan, 2003

<==o †Pachycephalosauria (Sternberg, 1945) Marya´nska & Osmólska, 1974 (thick-headed dinosaurs; paksupäät)
   |?- †Alaskacephale gangloffi Sullivan, 2006
   |?- †Dracorex hogwartsia Bakker, Sullivan, Porter, Larson & Saulsbury, 2006 [=? juveline Pachycephalosaurus Brown & Schlaikjer, 1943 sensu Horner & Goodwin, 2009]
   |?- †Ferganocephale adenticulatum Averianov, Martin & Bakirov, 2005
   |-- †Stenopelix valdensis Meyer, 1857
   `--+-- †Wannanosaurus yansiensis Hou, 1977; L.Cret. EAs.
      `--o †Goyocephalia
         |-- †Goyocephale lattimorei Perle, Marya´nska & Osmólska, 1982
         `--o †Homalocephaloidea Dong, 1974 sensu Sereno, 1990 [Homalocephalidae Dong, 1974 sensu lato]
            |-- †Homalocephale calathocercos Marya´nska & Osmólska, 1974
            |-- †Ornatotholus browni (Wall & Galton, 1979) Galton & Sues, 1983 [Stegoceras browni Wall & Galton, 1979]
            `--+-- †Yaverlandia bitholus Galton, 1971c
               `--o †Pachycephalosauridae Sternberg, 1945 [Tholocephalidae]
                  |?- †“Stegoceras” lambei Sternberg, 1945
                  |?- †Gravitholus sternbergi (Brown & Schlaikjer, 1943) [Troodon sternbergi Brown & Schlaikjer, 1943; Stegoceras sternbergi (Brown & Schlaikjer, 1943); Gravitholus albertae Wall, & Galton, 1979]
                  |-- †Stegoceras validum (Lambe, 1902) emend. Sues & Galton, 1987 [taxonomic history]
                  `--+-- †Pachycephalosauridae genera et species indet. [North American dwarf species]
                     `--o †Pachycephalosaurinae Sternberg, 1945
                        |--o “Tylocephalini”
                        |  |-- †Tylocephale gilmorei Marya´nska & Osmólska, 1974
                        |  `--o †Prenocephale Marya´nska & Osmólska, 1974
                        |     |-- †P. prenes Marya´nska & Osmólska, 1974
                        |     |-- †P. brevis (Lambe, 1918b) Sullivan, 2000 [Stegoceras breve Lambe, 1918b]
                        |     `-- †P. edmontonense (Brown & Schlaikjer, 1943) Sullivan, 2000 [Stegoceras edmontonense (Brown & Schlaikjer, 1943); Troodon edmontonense Brown & Schlaikjer, 1943]
                        `--o †Pachycephalosaurini Sternberg, 1945
                           |--o †Sphaerotholus Williamson & Carr, 2003
                           |  |-- †S. goodwini Williamson & Carr, 2003
                           |  |-- †S. sp. cf. S. goodwini [ Williamson & Carr, 2003]
                           |  `-- †S. buchholtzae Williamson & Carr, 2003 [TMP 87.113.3] [Troodon edmontonense Brown & Schlaikjer, 1943 (in partim); Stegoceras edmontonense (Brown & Schlaikjer, 1943) Griffen, 1989 (in partim); Prenocephale edmontonense (Brown & Schlaikjer, 1943) Sullivan, 2000 (in partim)]
                           `--+-- †Stygimoloch spinifer Galton & Sues, 1983 [Stenotholus kohleri Giffin, Gabriel & Johnson, 1987]  [=? subadult Pachycephalosaurus Brown & Schlaikjer, 1943 sensu Horner & Goodwin, 2009]
                              `--o †Pachycephalosaurus Brown & Schlaikjer, 1943 [taxonomic history]
                                 |?- †P. sp.
                                 `-- †P. wyomingensis (Gilmore, 1931) Brown & Schlaikjer, 1943 [taxonomic history]

Alternative phylogenies of Pachycephalosauria

<==o †Pachycephalosauria
   |?- †Dracorex
   |-- †Stenopelix
   `--+-- †Wannanosaurus
      `--o †Goyocephalia
         |-- †Goyocephale
         `--o †Homalocephaloidea
            |-- †Homalocephale
            |-- †Ornatotholus
            `--+-- †Yaverlandia
               `--o †Pachycephalosauridae
                  |-- †Stegoceras
                  `--+-- Pachycephalosauridae genera et species indet. [North American dwarf species]
                     `--o †Pachycephalosaurinae
                        |--o “Tylocephalini”
                        |  |-- †Tylocephale
                        |  `-- †Prenocephale
                        `--+--+-- †Colepiocephale
                           |  `-- †Hanssuessia
                           `--o †Pachycephalosaurini
                              |-- †Stygimoloch
                              `-- †Pachycephalosaurus

Pachycephalosauria incertae sedis:

    †“Troodon” bexelli Bohlin, 1953
    †“Troodon” edmontonense Brown & Schlaikjer, 1943 [CMN 8830] sensu Williamson & Carr, 2002 [Stegoceras edmontonense (Brown & Schlaikjer, 1943) Griffen, 1989 (in partim); Prenocephale edmontonense (Brown & Schlaikjer, 1943) Sullivan, 2000 (in partim)]

Reference(s):

• Averianov, A. O., Martin, T. & Bakirov, A. A., 2005: Pterosaur and dinosaur remains from the Middle Jurassic Balabansai Svita in the northern Fergana Depression, Kyrgyzstan (Central Asia).
  –Palaeontology: Vol. 48, #1, pp. 135-156
• Butler, R. J. & Zhao, Q., 2009: The small-bodied ornithischian dinosaurs Micropachycephalosaurus hongtuyanensis and Wannanosaurus yansiensis from the Late Cretaceous of China.
  –Cretaceous Research: Vol. 30, #1, pp. 63-77 [doi: 10.1016/j.cretres.2008.03.002]
• Dodson, P., 1990: Marginocephalia. 562-563.
  in Weishampel, D. B., Dodson, P., & Osmólska, H. (eds.), 1990: The Dinosauria.
  –University of California Press, Berkley, Los Angeles, Oxford, 1990 xvi-733
• Goodwin, M. B., Buchholtz, E. A. & Johnson, R. E., 1998: Cranial anatomy and diagnosis of Stygimoloch spinifer (Ornithischia: Pachycephalosauria) with comments on cranial display structures in agonistic behavior.
  –Journal of Vertebrate Paleontology: Vol. 18, #2, pp. 363-375
• Horner, J. R. & Goodwin, M. B., 2009: Extreme cranial ontogeny in the Upper Cretaceous dinosaur Pachycephalosaurus.
  –Plos One: Vol. 4, #10, pp. e7626(1-11) [doi: 10.1371/journal.pone.0007626]
• Keesey, T. M., 1996-2000: The Dinosauricon
  –iNet: The Dinosauricon: http://dinosauricon.com/
• Marya´nska, T., 1990: Pachycephalosauria. 564-577
  in Weishampel, D. B., Dodson, P., & Osmólska, H. (eds.), 1990: The Dinosauria.
  –University of California Press, Berkley, Los Angeles, Oxford, 1990 xvi-733
• Sereno, P. C., 2000: The fossil record, systematics and evolution of pachycephalosaurs and ceratopsians from Asia. 480-516
  in Benton, M. J., Shishkin, M. A., Unvin, D. M. & Kurochkin, E. N., (eds.) 2000: The Age of Dinosaurs in Russia and Mongolia.
  –Cambridge University Press, Cambridge, xxxix-696
• Sullivan, R. M., 2000: Stegoceras revisited.
  –Journal of Vertebrate Paleontology: Vol. 20, #3, suppl. to #3, 72A
• Sullivan, R. M., 2003: Revision of the dinosaur Stegoceras Lambe (Ornithischia, Pachycephalosauria).
  –Journal of Vertebrate Paleontology: Vol. 23, #1, pp. 181-207
• Sullivan, R. M., 2006: A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia).
  –New Mexico Museum of Natural History Bulletin 35: 347-365
• Williamson, T. E. & Carr, T. D., 2003: A new genus of derived pachycephalosaurian from western North America.
  –Journal of Vertebrate Paleontology: Vol. 22, #4, pp. 779-801