, Volume 95, Issue 6, pp 493–500

Digital preparation of a probable neoceratopsian preserved within an egg, with comments on microstructural anatomy of ornithischian eggshells


    • Division of PaleontologyAmerican Museum of Natural History
  • Mark A. Norell
    • Division of PaleontologyAmerican Museum of Natural History
  • Gerald Grellet-Tinner
    • Department of Geology and Geological EngineeringSouth Dakota School of Mines
  • Matthew R. Lewin
    • Department of Emergency MedicineUniversity of California, San Francisco School of Medicine
Original Paper

DOI: 10.1007/s00114-008-0347-2

Cite this article as:
Balanoff, A.M., Norell, M.A., Grellet-Tinner, G. et al. Naturwissenschaften (2008) 95: 493. doi:10.1007/s00114-008-0347-2


We describe the first known embryo of a neoceratopsian dinosaur, perhaps the most ubiquitous Laurasian group of Cretaceous dinosaurs, which is preserved completely enclosed within an egg. This specimen was collected from Late Cretaceous beds of southern Mongolia, which commonly preserve fossils of the neoceratopsian, Yamaceratops dorngobiensis. The small egg was scanned using high-resolution X-ray computed tomography and digitally prepared from the matrix. The preserved and imaged elements support a diagnosis of the embryo to Neoceratopsia and allow preliminary observations of ontogenetic transformations within this group. The addition of an embryo also adds another important data point to the already impressive postnatal ontogenetic series that are available for this clade.


OrnithischiaComputed tomographyEggshell microstructureEmbryo

Supplementary material (3 mb)
S1Spinning animation of the three-dimensional reconstruction of the skeletal elements contained within the egg. The matrix and eggshell have been rendered transparent (MOV 3.1 MB).

Copyright information

© Springer-Verlag 2008