Dinosaur eggs

Dinosaurs manage to intrigue people from all over the world, who are fascinated by this large and diverse group of animals that once dominated the Earth.  Scientists have learned about dinosaurs from a number of different sources, including the discovery of various body and trace fossils.  Dinosaur eggs are one particular representation of a dinosaur fossil, and in a few cases, an embryonic dinosaur has even been preserved and discovered within eggshells for scientists to study.  There are about 200 sites around the world where dinosaur egg fossils have been discovered, mostly in the terrestrial rocks that represent the Cretaceous age.  The majority of dinosaur eggs have been discovered in Asia, although other sites have been found in other locations around the world.  Just as dinosaur species varied dramatically in size, so too did the eggs that they produced, and the egg fossils that have been found and studied.

Dinosaur egg fossils are one of the ways that scientists learn about dinosaur behaviour, and together with other trace fossils and body fossils, are how people know so much about different dinosaur species.  The first discovery of a dinosaur eggshell was in 1859 in southern France, although it was not immediately recognised as belonging to a dinosaur.  While different interpretations of this discovery claimed that these eggs belonged to both large birds and giant crocodiles, in 1877 they were correctly identified as belonging to a dinosaur.  A number of different dinosaur egg fossils have been discovered and identified since this time.  Dinosaur eggs typically consist of a series of vertical units, which have grown from particular sites on the surface of the egg shell.  These basic vertical units can be organised in a number of different fashions, and dinosaur eggs are classified according to their configuration. 

Dinosaur eggs are classified in three different types:  spherulitic, prismatic, and ornithiod.  Spherulitic egg shells are seen in sauropods and hadrosaurs, and have a crystalline structure that shows spherical patterns.  Prismatic shells, in contrast, grow into spherical crystals in the lower portion and prismatic crystals in the upper portion.  Ornithoid eggs are the third type of dinosaur egg, and are generally seen in theropods.  This final structure is also seen in bird eggs, where the very bottom part of the shell exists as a separate unit to the rest of the egg.  In ornithoid eggs, the middle and upper portions of the shell are made up from a biocrystalline material with a spongy structure.  Dinosaur eggs are a great way for scientists to further classify different dinosaur species, and are also a great way for them to learn more about dinosaur biology and behaviour.