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.

  • Letter
  • Published:

Sauropod dinosaur embryos from the Late Cretaceous of Patagonia

Nature volume 396, pages 258–261 (1998)Cite this article

Abstract

Definitive non-avian dinosaur embryos, those contained inside fossil eggs, are rare1,2. Here we describe the first known unequivocal embryonic remains of sauropod dinosaurs—the only known non-avian dinosaur embryos from Gondwana—from a nesting ground in the Upper Cretaceous stage of Patagonia, Argentina. At this new site, Auca Mahuevo (Fig. 1), thousands of eggs are distributed over an area greater than 1 km2. The proportion of eggs containing embryonic remains is high: over a dozen in situ eggs and nearly 40 egg fragments encasing embryonic material were recovered. In addition to bone, these specimens contain large patches of fossil skin casts, the first definitive portions of integument ever reported for a non-avian dinosaur embryo. As morphology of the eggs enclosing these osseous and integumentary remains is identical, we propose that these specimens belong to the same sauropod species. This discovery allows the confident association of the megaloolithid type of dinosaur eggshell3 with sauropod dinosaurs.

The eggs and embryos were collected from the Anacleto Member of the Río Colorado Formation. Previous age assignments for the fossils from the Río Colorado Formation have ranged from Coniacian to Campanian30, a wide geochronological interval extending from about 89 Myr to about 71 Myr. The eggs and embryos are restricted to a 5-m-thick interval of silty, pale reddish-brown mudstone stratigraphically located just below the midpoint of a 25-m-thick sequence of siltstones and fine- to medium-grained sandstone. These sediments seem to represent shallow palaeochannel and associated overbank deposits laid down on a low-gradient floodplain. The eggs and embryos are preserved exclusively in the finer-grained, overbank silts and muds.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 2: Bone morphology of the sauropod embryos from Auca Mahuevo.
Figure 3: Natural cast of the integument of the sauropod embryos from Auca Mahuevo.
Figure 4: Eggshell morphology of the Auca Mahuevo embryos.

Similar content being viewed by others

References

  1. Carpenter, K., Hirsh, K. F. & Horner, J. R. Dinosaur Eggs and Babies (Cambridge Univ. Press, Cambridge, 1994).

    Google Scholar 

  2. Horner, J. R. in Encyclopedia of Dinosaurs (eds Currie, P. & Padian, K.) 45–50 (Academic Press, San Diego. 1997).

    Google Scholar 

  3. Mikhailov, K. E. Classification of fossil eggshells of amniotic vertebrates. Acta Palaeontol. Pol. 36, 193–238 (1991).

    Google Scholar 

  4. Wilson, J. A. & Sereno, P. C. Early evolution and higher-level phylogeny of sauropod dinosaurs. Soc. Vert. Paleontol. Mem. 5, 1–68 (1998).

    Article  Google Scholar 

  5. Upchurch, P. The evolutionary history of sauropod dinosaurs. Phil. Trans. R. Soc. Lond. B 349, 365–390 (1995).

    Article  ADS  Google Scholar 

  6. Calvo, J. O. Jaw mechanics in sauropod dinosaurs. Gaia 10, 183–193 (1994).

    Google Scholar 

  7. Horner, J. R. & Currie, P. J. in Dinosaur Eggs and Babies (eds Carpenter, K., Hirsh, K. F. & Horner, J. R.) 312–336 (Cambridge Univ. Press, Cambridge, 1994).

    Google Scholar 

  8. McIntosh, J. S. in The Dinosauria (eds Weishampel, D. B., Dodson, P. & Osmólska, H.) 345–401 (Univ. Calif. Press, Berkeley, 1990).

    Google Scholar 

  9. Madsen, J. H. J, McIntosh, J. S. & Berman, D. S. Skull and atlas-axis complex of the Upper Jurassic sauropod Camarasaurus Cope (Reptilia: Saurischia). Bull. Carnegie Mus. Nat. Hist. 31, 1–115 (1995).

    Google Scholar 

  10. Gauthier, J. Saurischian monophyly and the origin of birds. Mem. Calif. Acad. Sci. 8, 1–55 (1986).

    Google Scholar 

  11. Manning, T. W., Joysey, K. A. & Cruikshank, A. R. I. in Dinofest International (eds Wolberg, D. L., Stump, E. & Rosenberg, G. D.) 287–290 (Academy of the Natural Sciences, Philadelphia, 1997).

    Google Scholar 

  12. Czerkas, S. The history and interpretation of sauropod skin impressions. Gaia 10, 173–182 (1994).

    Google Scholar 

  13. Bonaparte, J. F. & Powell, J. E. Acontinental assemblage of tetrapods from the Upper Cretaceous beds of El Brete, northwestern Argentina (Sauropods-Coelurosauria-Carnosauria-Aves). Mem. Soc. Geol. Fr. 39, 19–28 (1980).

    Google Scholar 

  14. Ferguson, M. W. J. in Biology of the Reptilia Vol. 14(ed Gans, C.) 329–492 (John Wiley, New York, 1985).

    Google Scholar 

  15. Galton, P. Juveniles of the stegosaurian dinosaur Stegosaurus from the Upper Jurassic of North America. J. Vert. Paleontol. 2, 47–62 (1982).

    Article  Google Scholar 

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

    Google Scholar 

  17. Bray, E. S. & Hirsh, K. F. Eggshell from the Upper Jurassic Morrison Formation. Modern Geol. (in the press).

  18. Carpenter, K. & Alf, K. in Dinosaur Eggs and Babies (eds Carpenter, K., Hirsh, K. F. & Horner, J. R.) 15–30 (Cambridge Univ. Press, Cambridge, 1994).

    Google Scholar 

  19. Mikhailov, K. E. Fossil and recent eggshell in amniotic vertebrates: fine structure, comparative morphology and classification. Palaeontology 56, 1–80 (1997).

    Google Scholar 

  20. Powell, J. E. Hallazgo de huevos asignables a dinosaurios titanosauridos (Saurischia, Sauropoda) de la Provincia de Río Negro, Argentina. Acta Zool. Lilloana 41, 381–389 (1992).

    Google Scholar 

  21. Calvo, J. O., Engelland, S., Heredia, S. E. & Salgado, L. First record of dinosaur eggshells (?Sauropoda–Megaloolithidae) from Neuquén, Patagonia, Argentina. Gaia 14, 23–32 (1997).

    Google Scholar 

  22. Erben, H. K., Hoefs, J. & Wedepohl, K. H. Paleobiological and isotopic studies of eggshells from a declining dinosaur species. Paleobiology 5, 380–414 (1979).

    Article  CAS  Google Scholar 

  23. Sahni, A. & Khosla, A. Paleobiology, taphonomical and paleoenvironmental aspects of Indian Cretaceous sauropod nesting sites. Gaia 10, 215–223 (1994).

    Google Scholar 

  24. Norell, M. A. et al. Atheropod dinosaur embryo, and the affinities of the Flaming Cliffs dinosaur eggs. Science 266, 779–782 (1994).

    Article  ADS  CAS  Google Scholar 

  25. Horner, J. R. & Weischampel, D. B. Correction: A comparative embryological study of two ornithischian dinosaurs. Nature 383, 103 (1996).

    Article  ADS  CAS  Google Scholar 

  26. Britt, B. B. & Naylor, B. G. in Dinosaur Eggs and Babies (eds Carpenter, K., Hirsh, K. F. & Horner, J. R.) 256–264 (Cambridge Univ. Press, Cambridge, 1994).

    Google Scholar 

  27. Mohabey, D. M. Juvenile sauropod dinosaurs from Upper Cretaceous Lameta Formation of Panchmanhals District, Guajarat, India. J. Geol. Soc. India 30, 210–216 (1987).

    Google Scholar 

  28. Jain, S. in Dinosaur Tracks and Traces (eds Gillette, D. & Lockley, M.) 99–108 (Cambridge Univ. Press, Cambridge, 1989).

    Google Scholar 

  29. Bakker, R. The Dinosaur Heresies (William Morrow, New York, 1986).

    Google Scholar 

  30. Chiappe, L. M. & Calvo, J. O. Neuquenornis volans, a new Upper Cretaceous bird (Enantiornithes: Avisauridae) from Patagonia, Argentina. J. Vert. Paleontol. 14, 230–246 (1994).

    Article  Google Scholar 

Download references

Acknowledgements

We thank J. Clarke, O. DiIorio, J. Guevara, N. Klaiseburd, C. Mehling, P. Puerta, S. Salvidia, and S. Zetkus for field assistance; J. McIntosh, J. Gauthier, and E. Buffetaut for comments and reviews; A. Klaus for the SEMs; L. Meeker for the photographs; and S. Orell for illustrations and editing. This work was supported by the National Geographic Society, the InfoQuest Foundation, the Image & Chemical Analysis Lab (ICAL, MSU), the F. Chapman Fund (AMNH) and the Dirección de Cultura (Gobernación de la Provincia del Neuquén, Argentina).

Author information

Authors and Affiliations

  1. Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, 10024, New York, USA

    Luis M. Chiappe

  2. Museo Municipal ‘Carmen Funes’, 8318 Plaza Huincul, Neuquén, Argentina

    Rodolfo A. Coria

  3. Department of Vertebrate Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, 10024, New York, USA

    Lowell Dingus

  4. Department of Paleontology, Museum of the Rockies, Montana State University, Bozeman, 59717, Montana, USA

    Frankie Jackson

  5. Zoology Department, University of Cape Town, Private Bag, 7700, Rondebosch, South Africa

    Anusuya Chinsamy

  6. South African Museum, PO Box 81, Cape Town, 8000, South Africa

    Anusuya Chinsamy

  7. Department of Vertebrate Paleontology, Peabody Museum of Natural History, Yale University, New Haven, 06520, Connecticut, USA

    Marilyn Fox

Authors
  1. Luis M. Chiappe
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Rodolfo A. Coria
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Lowell Dingus
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Frankie Jackson
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Anusuya Chinsamy
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Marilyn Fox
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Luis M. Chiappe.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chiappe, L., Coria, R., Dingus, L. et al. Sauropod dinosaur embryos from the Late Cretaceous of Patagonia. Nature 396, 258–261 (1998). https://doi.org/10.1038/24370

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/24370

This article is cited by

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

Advanced 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