AGE:
Late Cretaceous (Campanian), Barun Goyot Formation, 75 million years ago

CLASSIFICATION:
SAUROPODA

The largest dinosaurs that ever lived, the sauropods, include such well-known forms as Brontosaurus - Apatosaurus from North America, Mamenchisaurus from China and Rhoetosaurus from Australia.

Although their bones are known from every continent except Antarctica, their eggs are known from only three places: The Peoples' Republic of Mongolia, Provence (France) and Patagonia, Argentina.

The eggs in this exhibition from Mongolia were laid in a depression scooped out of sand.

Examination of the microstructure of the eggshell indicates that the embryos died before the eggs hatched because the eggs were covered with water and the embryos drowned. In order for the embryos to obtain oxygen while in the egg, the surface of the shell was covered with 200,000-300,000 pores.

The volume of the individual eggs is 1.7-1.8 litres.