Pond-tortoise embryos

Four different kinds of eggs were available for study from the Upper Cretaceous of China. All of these were originally thought to be dinosaurian. But one of the small, nearly spherical eggs has now been shown to contain the complete, largely articulated skeleton of an embryonic pond-tortoise (emyid). The black preservation of the bones is somewhat different from that of the therizinosaur.

Although this egg lacks the glamour of the dinosaurs, it is probably the most perfectly preserved Upper Cretaceous embryo known. It is up to 40 million years older than the previous earliest record of this group of reptiles. In another disarticulated skeleton one of the smallest bones of the body, the stapes, which conducts vibrations from the ear-drum to the inner ear; is exquisitely preserved.

Images:

click here to view image of- pond tortoise (emyid) embryo showing the right side of the skull, with its large eye socket and tooth-like projections on the rim of the mouth. The skull is about 10 mm long. click here to view image of- pond tortoise embryo showing toe-bones and claws of both feet.

click here to view image of- another specimen of pond tortoise embryo showing the principal bone of the middle ear, the stapes, which is the trumpet-shaped object.

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• Acknowledgements
• Introduction
• Dinosaurs - Reptile and Bird Eggs
• Dinosaur Eggs and the Embryonic bones within the Eggs
• Extraction of the embryos
• What is so outstanding about this particular find?
• Preservation of soft tissues
• Pond-tortoise embryos
• Scavengers
• Moldy eggs?
• Dinosaur classification