Dinosaur Nesting and Eggs

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Both birds and reptiles lay eggs, so to say that dinosaur eggs were found does not support either side. However, if one were to find dinosaur eggs in groups, or young dinosaurs in the nest, that would be evidence of birdlike parenting. Reptiles abandon their eggs soon after they are laid and only bury them underground to protect them from predators. The first egg finds seemed to suggest that dinosaurs did abandon their eggs shortly after they were laid (see All American Dinosaur). However, new evidence found at the old sites changes the picture (particularly of one dinosaur) from an egg thief to a caring mother.

Oviraptor on nest....................................egg w/ fossil embryo

Oviraptor, meaning "egg thief", was discovered near a nest of eggs. Early scientists believed that the toothless dinosaur was in the process of stealing the eggs of Protoceratops (similar to Triceratops) at the time of a sand storm, and died in the attempt. Only a few years ago was it discovered who the eggs really belonged to. The skeleton of an Oviraptor was found on top of the eggs, in a brooding position like a bird (see picture above). The eggs belonged to Oviraptor, the supposed egg thief! Several of the eggs were excavated and the stone sediment that had filled them was dissolved with acid. Tiny bones of unhatched Oviraptors were discovered inside.

for more on how they uncover fossil embryos and eggs go to National Geographic's Egg Hunt

In some dinosaur nests in the American badlands, more than simply eggs were found. Young duckbill dinosaurs (picture above) were found together in a nest with crushed egg shells. The crushed egg shells and the size of the adolescent duckbills proved that the dinosaurs had been staying in the nests after their birth. The mother duckbill must have gathered food and fed her babies until they were able to walk and forage on their own. John Horner, who discovered the eggs in Montana, was surprised by the exactness with which the eggs were laid out. The arrangement of other unhatched nests near by and the young in the nest convinced him that dinosaurs cared for their young. Unhatched nests had the eggs arranged in an exact spiral, each an equal distance from the other and buried 1/2 way, tip down in sediment. Horner was convinced that that kind of precision would require a mother's intervention (Czerkas/Owen vol 1: 56). Horner also noticed that all of the nests that he found were the same distance apart, at a little more than the length of an adult dinosaur. He surmised that this meant that the dinosaurs traveled and nested in herds. (See Dinosaur Herds)

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