Cm 20 x 15 x 15

Dinosaur eggs are represented today as fossils. They represent that product of egg laying activity and can offer clues to how dinosaurs behaved.

Dinosaur eggs are known from about 200 sites around the world, the majority in Asia and mostly in terrestrial (nonmarine) rocks of Cretaceous Age (145 to 66 million years ago).

Fossil dinosaur eggs used to be the precious property of museums, but with the widespread diggings in China they are becoming available.

The dinosaur eggs went through a series of major events to become known to us today as fossils. After being laid, the egg was buried by a fine covering of sediment (maybe sand). This protected it from predation and scavenging and sealed it from the air (in particular oxygen) which would break it down and destroy the egg. Ground waters flowing through the sediment go through the egg and minerals precipitate from the solution into the egg.

The original shell material is actually little altered during fossilization as it is made up of the mineral calcite which is stable (resistant to change) during the fossilization process, although it may be recrystallised. This outer shell is hard and made up of a series of interlocking units, a mosaic of plates, with pores which allow the passage of air in and out of the egg. This allows the baby to breathe.

Two major types of dinosaur eggs are recognised: spheroidal and elongated. These types can be further sub-divided based on length/diameter ratios, the thickness of the shell, the type of pores and the surface of the egg (may be ornamented).

These specimen belong to the "spheroidal" category, and they are seen in sauropods and hadrosaurs.