Digimorph, An NSF Digital Library at UT Austin, Texas
Browse the Library by:
 Scientific Names
 Common Names
 What's Popular?
Learn More
Overview Pages
A Production of

Incisivosaurus gauthieriFossil, Oviraptorid
Dr. Amy Balanoff - Stony Brook University School of Medicine
Dr. Xing Xu, Dr. Yoshimura Kobayashi, Dr. Yusuke Matsufune, and Dr. Mark A. Norell
Incisivosaurus gauthieri
Click for help
Click for more information

Chinese Academy of Sciences (IVPP 13326) - holotype

Image processing: Dr. Amy Balanoff
Publication Date: 15 Jul 2009


The imagery on this page is the basis for a paper entitled Cranial osteology of the theropod dinosaur Incisivosaurus gauthieri (Theropoda: Oviraptorosauria), by A.M. Balanoff, X. Xu, Y. Kobayashi, Y. Matsufune, and M.A. Norell, 2009 (American Museum Novitates 3651:1-35). The abstract is as follows:

       We provide a description of the holotype skull of the unusual oviraptorosaur Incisivosaurus gauthieri.        Previous phylogenetic analyses have placed this taxon firmly within Oviraptorosauria near the base of        the clade; however, until now only a cursory description of this important specimen was available.        The presence of many primitive characteristics (e.g., maxillary and dentary teeth as well as an        extended palate and rostrum) indicates that the observed similarities between avians and derived        oviraptorids are convergences rather than shared derived characters. In addition, we clarify previous        descriptions of several ambiguous anatomical features, most notably of the palate. We also employ a        computed tomographic (CT) analysis, which allows for a more complete description of the braincase        and the reconstruction of an endocranial endocast. CT imagery reveals features that were before        unobtainable, such as the presence of a replacement tooth behind the large rodentiform incisor in        the premaxilla. This arrangement indicates that although the incisiform teeth of I. gauthieri are        morphologically distinct they are replaced in typical archosaurian fashion.

About the Species

This specimen, the holotype and only known specimen, was discovered in the Early Cretaceous rocks of northeastern China. It was collected from the lower part of the Yixian Formation.

About this Specimen

The specimen was scanned at Stony Brook University medical scanning facility. It was scanned along the coronal axis for a total of 404 slices, and each 512X512 pixel slice is 0.310 mm thick.

About the


Alonso, P.D., A.C. Milner, R.A. Ketcham, M.J. Cookson, and T.B. Rowe. 2004. The avian nature of the brain        and inner ear of Archaeopteryx. Nature 430: 666–669.
Balanoff, A.M., G.S. Bever, and T. Ikejiri. In press. The braincase of Apatosaurus (Dinosauria: Sauropoda)        based on computed tomography of a new specimen with comments on variation and evolution in        sauropod neuroanatomy. American Museum Novitates.
Barrett, P.M., and J.M. Hilton. 2006. The Jehol biota (Lower Cretaceous, China): new discoveries and        future prospects. Integrative Zoology 1: 15–17.
Barsbold, R. 1976. On a new Late Cretaceous family of small theropods (Oviraptoridae fam. n.) of Mongolia.        Doklady Akademia Nauk SSSR 226: 685–688. [In Russian]
Barsbold, R. 1981. Toothless dinosaurs of Mongolia. Joint Soviet-Mongolian Paleontological Expedition        Transactions 15: 28–39. [In Russian]
Barsbold, R. 1983. Carnivorous dinosaur from the Cretaceous of Mongolia. Trudy, Sovmestnaa Sovetsko-       Mongol’skaa palaeontologiceskaa ekspedicia 19: 1–19.
Barsbold, R. 1986. Raubdinosaurier Oviraptoren. In E.I. Vorobyeva (editor), Herpetologische        Untersuchungen in der Mongolischen Volskrepublik. Akademia Nauk SSSR Inst. Evolyucionnoy        Morfologii i Ekologii Zhivotnikh im: 210–223. Moskva: A.M. Severtsova. [In Russian with German Summary]
Barsbold, R. 1997. Oviraptorosauria. In P.J. Currie and K. Padian (editors), Encyclopedia of Dinosaurs: 505–       509. New York: Academic Press.
Barsbold, R., H. Osmólska, M. Watabe, P.J. Currie, and K. Tsogtbaatar. 2000. A new oviraptorosaur        (Dinosauria: Theropoda) from Mongolia: the first dinosaur with a pygostyle. Acta Palaeontologica        Polonica 45: 97–106.
Baumel, J.J., and L.M. Witmer. 1993. Osteologia. In J.J. Baumel, A.S. King, J.E. Breazile, H.E. Evans, and J.C.        Vanden Berge (editors), Handbook of Avian Anatomy: Nomina Anatomica Avium, 2nd ed, Publications of        the Nuttall Ornithological Club 23: 45–113.
Brochu, C.A. 2000. Digitally-rendered endocast for Tyrannosaurus rex. Journal of Vertebrate Paleontology        20: 1–6.
Carlson, W.D., T. Rowe, R.A. Ketcham, and M.W. Colbert. 2003. Geological applications of high-resolution X-       ray computed tomography in petrology, meteoritics and paleontology. In F. Mees, R. Swennen, M. Van        Geet, and P. Jacobs (editors), Applications of X-ray Computed Tomography in the Geosciences 215: 7–       22. London: Geological Society.
Chiappe, L., M.A. Norell, and J.M. Clark. 1998. The skull of the stem-group bird Mononykus. Nature 392: 275–       278.
Clark, J.M., A. Perle, and M. Norell. 1994. The skull of Erlicosaurus andrewsi, a Late Cretaceous        "segnosaur" (Theropoda: Therizinosauridae) from Mongolia. American Museum Novitates 3115: 1–39.
Clark, J.M., M.A. Norell, and R. Barsbold. 2001. Two new oviraptorids (Theropoda: Oviraptorosauria), Upper        Cretaceous Djadokhta Formation, Ukhaa Tolgod, Mongolia. Journal of Vertebrate Paleontology 21: 209–       213.
Clark, J.M., M.A. Norell, and T. Rowe. 2002. Cranial anatomy of Citipati osmolskae (Theropoda,        Oviraptorosauria), and a reinterpretation of the holotype of Oviraptor philoceratops. American        Museum Novitates 3364: 1–24.
Clark, J.M., M. Norell, and L. Chiappe. 1999. An oviraptorid skeleton from the Late Cretaceous of Ukhaa        Tolgod, Mongolia, preserved in an avian-like brooding position over an oviraptorid nest. American        Museum Novitates 3265: 1–36.
Currie, P.J. 1985. Cranial anatomy of Stenonychosaurus inequalis (Saurischia, Theropoda) and its bearing on        the origin of birds. Canadian Journal of Earth Sciences 22: 1643–1658.
Currie, P.J. 1995. New information on the anatomy and relationships of Dromaeosaurus albertensis        (Dinosauria: Theropoda). Journal of Vertebrate Paleontology 15: 576–591.
Currie, P.J., and X.-J. Zhao. 1993. A new troodontid (Dinosauria, Theropoda) braincase from the Dinosaur        Park Formation (Campanian) of Alberta. Canadian Journal of Earth Sciences 30: 2231–2247.
Dong Z.-M., and P.J. Currie. 1996. On the discovery of an oviraptorid skeleton on a nest of eggs at Bayan        Mandahu, Inner Mongolia, People's Republic of China. Canadian Journal of Earth Sciences 33: 631–636.
Elzanowski, A. 1999. A comparison of the jaw skeleton in theropods and birds, with a description of the        palate in the Oviraptoridae. Smithsonian Contributions to Paleobiology 89: 311–323.
Felsenstein, J. 1985. Phylogenies and the comparative method. American Naturalist 125: 1–15.
Franzosa, J. 2004. Evolution of the Brain in Theropoda (Dinosauria). Ph.D. diss. The University of Texas at        Austin, 357 pp.
Franzosa, J, and T. Rowe. 2005. Cranial endocast of the Cretaceous theropod dinosaur Acrocanthosaurus        atokensis. Journal of Vertebrate Paleontology 25: 859–864.
Gauthier, J.A., 1986. Saurischian monophyly and the origin of birds. Memoir of the California Academy of        Sciences 8: 1–55.
Goodrich, E.S. 1930 [1986 reprint]. Studies on the Structure and Development of Vertebrates. Chicago:        University of Chicago Press. 837 pp.
Holtz, T.R. 1998. A new phylogeny of the carnivorous dinosaurs. Gaia 15: 5–61.
Hopson, J.A. 1977. Relative brain size and behavior in archosaurian reptiles. Annual Review of Ecology and        Systematics 8: 429–448.
Hopson, J.A. 1979. Paleoneurology. In C. Gans, R.G. Northcutt, and P. Ulinski (editors), Biology of the        Reptilia, vol. 9: 39–146. London: Academic Press.
Hwang, S.H., M.A. Norell, Q. Ji, and K. Gao. 2004. A large compsognathid from the Early Cretaceous Yixian        Formation of China. Journal of Systematic Palaeontology 2: 13–30.
Jerison, H.J. 1969. Brain evolution and dinosaur brains. American Naturalist 103: 575–588.
Ji, Q., and S.A. Ji. 1997. Protarchaeopterygid bird (Protarchaeopteryx gen. nov.)—fossil remains of        archaeopterygids from China. Chinese Geology 238: 38–41.
Ji, Q., M.A. Norell, K.-Q. Gao, S.-A. Ji, and D. Ren. 2001. The distribution of integumentary structures in a        feathered dinosaur. Nature 410: 1084–1088.
Ji, Q., P.J. Currie, M.A. Norell, and S.-A. Ji. 1998. Two feathered dinosaurs from northeastern China.        Nature 393: 753–761.
Ji, Q., M.A. Norell, P.J. Makovicky, K.-Q. Gao, S. Ji, and C. Yuan. 2003. An early ostrich dinosaur and        implications for ornithomimosaur phylogeny. American Museum Novitates 3420: 1–19.
Kundrát, M. 2007. Avian-like attributes of a virtual brain model of the oviraptorid theropod Conchoraptor        gracilis. Naturwissenschaften 94: 499–504.
Kundrát, M., and J. Janácek. 2007. Cranial pneumatization and auditory perceptions of the oviraptorid        dinosaur Conchoraptor gracilis (Theropoda, Maniraptora) from the Late Cretaceous of Mongolia.        Naturwissenschaften 94: 769–778.
Kurochkin, E.N., G.J. Dyke, S.V. Saveliev, E.M. Pevushov, and E.V. Popov. 2007. A fossil brain from the        Cretaceous of European Russia and avian sensory evolution. Biology Letters 3: 309–313.
Kurzanov, S.M. 1987. Avimimidae and the problem of the origin of birds. Transactions of the Soviet-       Mongolian Paleontological Expedition 31: 1–92. [in Russian]
Larsson, H.C.E., P.C. Sereno, and J.A. Wilson. 2000. Forebrain enlargement among nonavian theropod        dinosaurs. Journal of Vertebrate Paleontology 20: 615–618.
Lü, J. 2002. A new oviraptorosaurid (Theropoda: Oviraptorosauria) from the Late Cretaceous of southern        China. Journal of Vertebrate Paleontology 22: 871–875.
Lü, J. 2005. Oviraptorid dinosaurs from southern China. Beijing: Geological Publishing House. 200 pp.
Lü, J., Y. Tomida, Y. Azuma, Z. Dong, and Y.-N. Lee. 2004. New oviraptorid dinosaur (Dinosauria:        Oviraptorosauria) from the Nemegt Formation of southwestern Mongolia. Bulletin of the National        Science Museum, Tokyo, ser. C 30: 95–130.
Makovicky, P.J., and H.-D. Sues. 1998. Anatomy and phylogenetic relationships of the theropod dinosaur        Microvenator celer from the Lower Cretaceous of Montana. American Museum Novitates 3240: 1–27.
Makovicky, P.J., M.A. Norell, and J.M. Clark. 2003. Osteology and relationships of Byronosaurus jaffei        (Theropoda: Troodontidae). American Museum Novitates 3402: 1–32.
Maryanska, T., and H. Osmólska. 1997. The quadrate of oviraptorid dinosaurs. Acta Palaeontologia Polonica        42: 377–387.
Maryanska, T., H. Osmólska, and M. Wolson. 2002. Avialan status for Oviraptorosauria. Acta Palaeontologica        Polonica 47: 97–116.
Norell, M.A, J.M. Clark, D. Dashzeveg, R. Barsbold, L.M. Chiappe, A.R. Davidson, M.C. McKenna, and M.J.        Novacek. 1994. A theropod dinosaur embryo, and the affinities of the Flaming Cliffs Dinosaur eggs.        Science 266: 779–782.
Norell, M.A, J.M. Clark, L.M. Chiappe, and D. Dashzeveg. 1995. A nesting dinosaur. Nature 378:774–776.
Norell, M.A., J.M. Clark, and L.M. Chiappe. 2001. An embryo of an oviraptorid (Dinosauria: Theropoda) from        the Late Cretaceous of Ukhaa Tolgod, Mongolia. American Museum Novitates 3315: 1–17.
Norell, M.A., P.J. Makovicky, and J.M. Clark. 2000. A new troodontid from Ukhaa Tolgod, Mongolia. Journal        of Vertebrate Paleontology 20: 7–11.
Norell, M.A., P.J. Makovicky, and J.M. Clark. 2004. The braincase of Velociraptor. In P.J. Currie, E.B.        Koppelhus, M.A. Shugar, and J.L. Wright (editors), Feathered Dragons: Studies on the Transition from        Dinosaurs to Birds: 133–143. Bloomington: Indiana Press.
Norell, M.A., and M. Ellison. 2005. Unearthing the Dragon: The Great Dinosaur Discovery. New York: Pi        Press. 254 pp.
Norell, M.A., and X. Xu. 2005. Feathered dinosaurs. Annual Review of Earth and Planetary Sciences 33: 277–       299.
Norell, M.A., J.M. Clark, A.H. Turner, P.J. Makovicky, R. Barsbold, and T. Rowe. 2006. A new dromaeosaurid        theropod from Ukhaa Tolgod (Ömnögov, Mongolia). American Museum Novitates 3545: 1–51.
Osborn, H. F. 1903. Ornitholestes hermanni, a new compsognathid dinosaur from the upper Jurassic.        Bulletin of the American Museum of Natural History 19: 459–464.
Osmólska, H. 1981. Coosified tarsometatarsi in theropod dinosaurs and their bearing on the problem of bird        origins. In Z. Kielen-Jaworowski (editor), Results of the Polish–Mongolian Palaeontological Expeditions,        Part IX. Palaeontologia Polonica 42: 79–95.
Osmólska, H. 2004. Evidence on relation of brain to endocranial cavity in oviraptorid dinosaurs. Acta        Palaeontologica Polonica 49: 321–324.
Osmólska, H., P.J. Currie, and R. Barsbold. 2004. Oviraptorosauria. In D.B. Weishampel, P. Dodson, and H.        Osmólska (editors), The Dinosauria, 2nd ed.: 165–184. Berkeley, University of California Press.
Patterson, C. 1982. Morphological characters and homology. In K.A. Joysey and A.E. Friday (editors),        Problems of Phylogenetic Reconstruction: 21–74. London: Academic Press.
de Pinna, M.C.C. 1991. Concepts and tests of homology in the cladistic paradigm. Cladistics 7: 367–394.
Rogers, S.W. 1999. Allosaurus, crocodiles, and birds: evolutionary clues from spiral computed tomography        of an endocast. Anatomical Record 257: 162–173.
Romer, A.S. 1956. Osteology of the Reptiles. Chicago: University of Chicago Press. 772 pp.
Senter, P. 2007. A new look at the phylogeny of Coelurosauria (Dinosauria: Theropoda). Journal of        Systematic Palaeontology 5: 429–463.
Senter, P., R. Barsbold, B.B. Britt, and D.A. Burnham. 2004. Systematics and evolution of Dromaeosauridae.        Bulletin of Gunma Natural History Museum 8: 1–20.
Sues, H.-D. 1997. On Chirostenotes, a Late Cretaceous oviraptorosaur (Dinosauria: Theropoda) from western        North America. Journal of Vertebrate Paleontology 17: 698–716.
Swisher III, C.C., Y.-Q. Wang, X.-L. Wang, X. Xu, Y. Wang. 1999. Cretaceous age for the feathered dinosaurs        of Liaoning, China. Nature 400: 58–61.
Swisher III, C.C., X.-L. Wang, Z.-H. Zhou, Y.-Q. Wang, F. Jin, J.-Y. Zhang, X. Xu, and Y. Wang. 2002. Further        support for a Cretaceous age for the feathered dinosaur beds of Liaoning, China: new 40Ar/39Ar        dating of the Yixian and Tuchengzi formations. Chinese Science Bulletin 47: 135–138.
Turner, A.H., D. Pol, J.A. Clarke, G.M. Erickson, and M.A. Norell. 2007. A basal dromaeosaurid and size        evolution preceding avian flight. Science 317: 1378–1381.
Wang, X., and X. Xu. 2001 A new iguanodontid (Jinzhousaurus yangi gen. et sp. nov.) from the Yixian        Formation of western Liaoning, China. Chinese Science Bulletin 46: 1669–1672.
Witmer, L.M. 1990. The craniofacial air sac system of Mesozoic birds (Aves). Zoological Journal of the        Linnean Society 100: 327–378.
Witmer, L.M. 1995. The extant phylogenetic bracket and the importance of reconstructing soft tissues in        fossils. In J.J. Thomason (editor), Functional Morphology in Vertebrate Paleontology. Cambridge:        Cambridge University Press.
Witmer, L.M. 1997. The evolution of the antorbital cavity in archosaurs: a study in soft-tissue        reconstruction in the fossil record with an analysis of the function of pneumaticity. Journal of        Vertebrate Paleontology Memoir 3. Journal of Vertebrate Paleontology 17(supplement to 1): 1–73.
Xu, X., X.-L. Wang, and X.-C. Wu. 1999. A dromaeosaurid dinosaur with filamentous integument from the        Yixian Formation of China. Nature 401: 262–266.
Xu, X., Y.N. Chieng, X.-L. Wang, and C.-H. Chang. 2002a. An unusual oviraptorosaurian dinosaur from China.        Nature 419: 291–293.
Xu, X., P.J. Makovicky, X.-L. Wang, M.A. Norell, and H.-L. You. 2002b. A ceratopsian dinosaur from China        and the early evolution of Ceratopsia. Nature 416: 314–317.
Xu, X., M.A. Norell, X.-L. Wang, P.J. Makovicky, and X.-C. Wu. 2002c. A basal troodontid from the Early        Cretaceous of China. Nature 415: 780–784.
Xu, X., Z. Zhou, X. Wang, X. Kuang, F. Zhang, and X. Du. 2003. Four-winged dinosaurs from China. Nature        421: 335–340.
Xu, X., and M.A. Norell. 2004. A new troodontid dinosaur from China with avian-like sleeping posture.        Nature 431: 838–841.
Xu, X., J.M. Clark, C.A. Forster, M.A. Norell, G.M. Erickson, D.A. Eberth, C. Jia, and Q. Zhao. 2005. A basal        tyrannosaurid dinosaur from the Late Jurassic of China. Nature 439: 715–718.
Zhou, Z.-H., X.-L. Wang, F.-C. Zhang, and X. Xu. 2000. Important features of Caudipteryx—evidence from        two nearly complete new specimens. Vertebrate Palasiatica 38: 243–254.
Zhou, Z., P.M. Barrett, and J. Hilton. 2003. An exceptionally preserved lower Cretaceous ecosystem.        Nature 421: 807–814.

& Links
Skull with endocast roll movie

Click on the thumbnail to the left for a roll animation (2.6 mb) of the Incisivosaurus cranial endocast highlighted in blue within the skull, which is rendered semi-transparent.

endocast roll movie

Click on the thumbnail to the left for a roll animation (1.7 mb) of the isolated Incisivosaurus cranial endocast.

Skull with endocast yaw movie

Click on the thumbnail to the left for a yaw animation (2.3 mb) of the Incisivosaurus cranial endocast highlighted in blue within the skull, which is rendered semi-transparent.

endocast yaw movie

Click on the thumbnail to the left for a yaw animation (2.8 mb) of the isolated Incisivosaurus cranial endocast.

Skull with endocast pitch movie

Click on the thumbnail to the left for a pitch animation (1.5 mb) of the Incisivosaurus cranial endocast highlighted in blue within the skull, which is rendered semi-transparent.

endocast pitch movie

Click on the thumbnail to the left for a pitch animation (1.7 mb) of the isolated Incisivosaurus cranial endocast.


To cite this page: Dr. Amy Balanoff, Dr. Xing Xu, Dr. Yoshimura Kobayashi, Dr. Yusuke Matsufune, and Dr. Mark A. Norell, 2009, "Incisivosaurus gauthieri" (On-line), Digital Morphology. Accessed July 12, 2024 at http://digimorph.org/specimens/Incisivosaurus_gauthieri/.

©2002-20019 - UTCT/DigiMorph Funding by NSF