, Volume 92, Issue 10, pp 477–482 | Cite as

Minute theropod eggs and embryo from the Lower Cretaceous of Thailand and the dinosaur-bird transition

  • Eric Buffetaut
  • Gerald Grellet-Tinner
  • Varavudh Suteethorn
  • Gilles Cuny
  • Haiyan Tong
  • Adrijan Košir
  • Lionel Cavin
  • Suwanna Chitsing
  • Peter J. Griffiths
  • Jérôme Tabouelle
  • Jean Le Loeuff
Short Communication


We report on very small fossil eggs from the Lower Cretaceous of Thailand, one of them containing a theropod embryo, which display a remarkable mosaic of characters. While the surficial ornamentation is typical of non-avian saurischian dinosaurs, the three-layered prismatic structure of the eggshell is currently known only in extant and fossil eggs associated with birds. These eggs, about the size of a goldfinch's, mirror at the reproductive level the retention of small body size that was paramount in the transition from non-avian theropods to birds. The egg-layer may have been a small feathered theropod similar to those recently found in China.


Cretaceous Early Cretaceous Small Body Size Functioning Ovary Modern Bird 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was supported by the TRF-CNRS Special Programme for Biodiversity Research and Training, the Thai Department of Mineral Resources, the ECLIPSE 2 Programme of CNRS, the Jurassic Foundation, the Danish Natural Sciences Research Council, the Carlsberg Foundation, the Thai National Science Centre for Education, the Espéraza Dinosaur Museum, the exchange programme between CNRS and the Slovenian Academy of Arts and Sciences, the Department of Earth Sciences of the University of Southern California, the Natural History Museum of Los Angeles County, and the Geological Society of America. Thanks to Patrick De Wever (Muséum National d'Histoire Naturelle, Paris), Anne-Marie Lézine (CNRS, Gif-sur-Yvette) and F. Corsetti (Los Angeles) for their help with microscopical studies, to Luis Chiappe (Natural History Museum of Los Angeles County) for his support, to Rodolphe Gromberg (Paris), Didier Descouens and Jacques Treil (Toulouse) for their attempts at scanning the Phu Phok eggs, and to the three anonymous referees for their useful comments.


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Eric Buffetaut
    • 1
  • Gerald Grellet-Tinner
    • 2
    • 3
  • Varavudh Suteethorn
    • 4
  • Gilles Cuny
    • 5
  • Haiyan Tong
    • 1
  • Adrijan Košir
    • 6
  • Lionel Cavin
    • 7
  • Suwanna Chitsing
    • 8
  • Peter J. Griffiths
    • 9
  • Jérôme Tabouelle
    • 10
  • Jean Le Loeuff
    • 7
  1. 1.CNRS (UMR 5125, Paléoenvironnements et Paléobiosphère)ParisFrance
  2. 2.Department of Vertebrate PaleontologyNatural History Museum of Los Angeles CountyLos AngelesUSA
  3. 3.Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesUSA
  4. 4.Department of Mineral ResourcesBangkokThailand
  5. 5.Geological Museum, Øster Voldgade 5–7Copenhagen KDenmark
  6. 6.Institute of Palaeontology ZRC SAZULjubljanaSlovenia
  7. 7.Musée des DinosauresEspérazaFrance
  8. 8.National Science Centre for EducationBangkokThailand
  9. 9.University of Wolverhampton, School of Applied SciencesWolverhamptonUK
  10. 10.Musée municipalElbeuf-sur-SeineFrance

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