Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The skull of a relative of the stem-group bird Mononykus

Abstract

In joint expeditions, researchers from the American Museum of Natural History and the Mongolian Academy of Sciences have recovered over 20 alvarezsaurid (Theropoda: Aves) specimens in the Late Cretaceous beds of Mongolia's Gobi Desert1. Here we describe a new taxon that is closely related to Mononykus2,3. This new taxon is represented by two exquisitely preserved skulls — the first known for Alvarezsauridae — details of which support the theory that the group is related to birds4,5. This theory was first put forward on the basis of primarily postcranial evidence2,3, including the presence of avian characteristics such as the absence of a contact between the jugal and postorbital, and between the quadratojugal and squamosal, articulations. Other earlier evidence that suggested that the alvarezsaurids were birds included the presence of a movable joint between the quadratojugal and quadrate, separate squamosal and braincase articulations of the quadrate, confluence between the caudal tympanic recess and columellar recess, a triradiate palatine, an unusually large foramen magnum, and the loss of a coronoid bone. The configuration of the temporal region of the skull and its articulation with the rostrum indicate the capability for prokinetic movement in which flexing occurs at the junction of the upper jaw and neurocranium, and support the idea that prokinesis preceded other types of avian intracranial kinesis.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Skull and jaw of Shuvuuia deserti (MGI 100/1001).
Figure 2: Skull and right jaw of Shuvuuia deserti (MGI 100/1001) in dorsal (a), ventral (b), and caudal (c) views.
Figure 3: Skull and jaws of Shuvuuia deserti (MGI 100/977) in dorsal (a) and ventral (b) views.
Figure 4: Taxonomy of Shuvuuia deserti and of Alvarezsauridae.

References

  1. Dashzeveg, D.et al. Extraordinary preservation in a new vertebrate assemblage from the Late Cretaceous of Mongolia. Nature 374, 446–449 (1995).

    ADS  Article  Google Scholar 

  2. Perle, A., Norell, M. A., Chiappe, L. M. & Clark, J. M. Flightless bird from the Cretaceous of Mongolia. Nature 362, 623–626 (1993).

    ADS  Article  Google Scholar 

  3. Perle, A.et al. Skeletal morphology of Mononykus olecranus (Theropoda: Avialae) from the Late Cretaceous of Mongolia. Am. Mus. Novit. 3105, 1–29 (1994).

    Google Scholar 

  4. Chiappe, L. M., Norell, M. A. & Clark, J. M. Phylogenetic position of Mononykus from the Upper Cretaceous of the Gobi Desert. Mem. Queens. Mus. 39, 557–582 (1996).

    Google Scholar 

  5. Chiappe, L. M., Norell, M. A. & Clark, J. M. Mononykus and birds: methods and evidence. Auk 114, 300–302 (1997).

    Article  Google Scholar 

  6. Jerzykiewicz, T. & Russell, D. A. Late Mesozoic stratigraphy and vertebrates from the Gobi Basin. Cretac. Res. 12, 345–377 (1991).

    Article  Google Scholar 

  7. Chiappe, L. M. Late Cretaceous birds of southern South America: anatomy and systematics of Enantiornithes and Patagopteryx deferrariisi. Münchener Geowiss. Ab. A 30, 203–244 (1996).

    Google Scholar 

  8. Currie, P. J. New information on the anatomy and relationships of Dromaeosaurus albertensis (Dinosauria, Theropoda). J. Vert. Paleontol. 15, 576–591 (1995).

    Article  Google Scholar 

  9. Weishampel, D. B., Dodson, P. & Osmólska, H. The Dinosauria (Univ. of California Press, Berkeley, 1990).

    Google Scholar 

  10. Cracraft, J. The lacrimal–ectethmoid bone complex in birds: a single character analysis. Am. Midl. Nat. 80, 316–359 (1968).

    Article  Google Scholar 

  11. Romer, A. S. Osteology of the Reptiles (Univ. Chicago Press, 1956).

    Google Scholar 

  12. Zusi, R. L. in The Skull Vol. 2(eds Hanken, J. & Hall, B. I.) 391–437 (Univ. Chicago Press, 1993).

    Google Scholar 

  13. Elzanowski, A. & Wellnhofer, P. Cranial morphology of Archaeopteryx: evidence from the seventh skeleton. J. Vert. Paleontol. 16, 81–94 (1996).

    Article  Google Scholar 

  14. Sanz, J. L.et al. Anestling bird from the Early Cretaceous of Spain: implications for avian skull and neck evolution. Science 276, 1543–1546 (1997).

    CAS  Article  Google Scholar 

  15. Zusi, R. L. Afunctional and evolutionary analysis of rhynchokinesis in birds. Smithson. Contr. Zool. 395, 1–40 (1985).

    Google Scholar 

  16. Simonetta, A. M. On the mechanical implications of the avian skull and their bearing on the evolution and classification of birds. Q. Rev. Biol. 35, 206–220 (1960).

    Article  Google Scholar 

  17. Bock, W. J. Kinetics of the avian skull. J. Morphol. 114, 1–42 (1964).

    Article  Google Scholar 

  18. Bühler, P. in The Beginnings of Birds (eds Hecht, M. K., Ostrom, J. H., Viohl, G. & Wellnhofer, P.) 135–140 (Proc. Int. Archaeopteryx Conf., Eichstätt, 1985).

    Google Scholar 

  19. Hou, L., Martin, L. D., Zhou, Z. & Feduccia, A. Early adaptive radiation of birds: evidence from fossils from northeastern China. Science 274, 1164–1167 (1996).

    ADS  CAS  Article  Google Scholar 

  20. Bühler, P., Martin, L. D. & Witmer, L. M. Cranial kinesis in the Late Cretaceous birds Hesperornis and Parahesperornis. Auk 105, 111–122 (1988).

    Google Scholar 

  21. Martin, L. D. & Rinaldi, C. How to tell a bird from a dinosaur. Maps Digest 17, 190–196 (1994).

    Google Scholar 

  22. Feduccia, A. The Origin and Evolution of Birds (Yale Univ. Press, New Haven, 1996).

    Google Scholar 

  23. Sereno, P. The origin and evolution of dinosaurs. Ann. Rev. Earth Planet. Sci. 25, 435–489 (1997).

    ADS  CAS  Article  Google Scholar 

  24. Novas, F. E. Alvarezsauridae, Cretaceous maniraptorans from Patagonia and Mongolia. Mem. Queens. Mus. 39, 675–702 (1996).

    Google Scholar 

  25. Novas, F. E. Anatomy of Patagonykus puertai (Theropoda, Maniraptora, Alvarezsauridae) from the Late Cretaceous of Patagonia. J. Vert. Paleontol. 17, 137–166 (1997).

    Article  Google Scholar 

  26. Forster, C. A., Chiappe, L. M., Krause, D. W. & Sampson, S. D. The first Cretaceous bird from Madagascar. Nature 382, 532–534 (1996).

    ADS  CAS  Article  Google Scholar 

  27. Pérez-Moreno, B. P.et al. Aunique multitoothed ornithomimosaur from the Lower Cretaceous of Spain. Nature 370, 363–367 (1994).

    ADS  Article  Google Scholar 

  28. Clark, J. M., Perle, A. & Norell, M. A. The skull of Erlicosaurus andrewsi, a Late Cretaceous “Segnosaur” (Theropoda: Therizinosauridae) from Mongolia. Am. Mus. Novit. 3115, 1–39 (1994).

    Google Scholar 

  29. Osmólska, H., Roniewicz, E. & Barsbold, R. Anew dinosaur, Gallimimus bullatus n. gen. n. sp. (Ornithomimidae) from the Upper Cretaceous of Mongolia. Palaeontol. Pol. 27, 103–143 (1972).

    Google Scholar 

Download references

Acknowledgements

We thank A. Davidson and M. Ellison for the preparation and illustration of the specimens, respectively, and A. Milner, L. Witmer, G. Zweers, and J. Vanden Berge for useful reviews and discussions. The Chapman and Frick Memorial Funds of the AMNH and the National Science Foundation provided support for this research.

Author information

Authors and Affiliations

Authors

Supplementary Information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Chiappe, L., Norell, M. & Clark, J. The skull of a relative of the stem-group bird Mononykus. Nature 392, 275–278 (1998). https://doi.org/10.1038/32642

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/32642

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing