Dinosaur - Predation Of Eggs
Why would any animal prey on eggs? Eggs are highly nutritious food, rich in proteins. Even the shell provides calcium carbonate. Evidence for predation is rare in the fossil record. Egg predators today include jackals, hyenas, primates, vultures, crows, gulls, and lizards and snakes. It is likely that egg predation also occurred during the reign of the dinosaurs.The theropod dinosaurs Oviraptor and Troodon have been accused in the past of preying on the eggs. Evidence now indicates they could actually be caring for the eggs. So although evidence for dinosaur egg predation by dinosaurs is dubious, it still probably happened.
Dinosaur eggs and nests are rare before the Cretaceous. This could mean one of two things:
1. There were fewer eggs before the Cretaceous.
2. The eggs had a less chance of making it into the fossil record before the Cretaceous.
The first possibility is unlikely. There is no evidence that pre-Cretaceous dinosaurs laid fewer eggs, or that they were overall rarer, than their Cretaceous counterparts. The second possibility is more likely. It has been suggested (Sochava 1969) that pre-Cretaceous eggs were pliable and non-calcareous. Sochava suggested the calcareous dinosaur egg developed in response to aridity in the Cretaceous, became harder and more likely to fossilize.
In the Cretaceous the eggs also appear ornamented. Ornamentation can be broadly divided into two types: longitudinal ridges seen in vertically or sub-vertically arranged eggs or multi-directional or nodular ornamentation seen in randomly laid eggs (Moratalla 1994). Ornamentation on the eggs allowed them to be buried after laying; the ornamentation allowed the flow of air between the ground and the egg. The ability to bury the eggs may have been an advance in the behaviour of dinosaurs, and it may have contributed to their improved preservation in the Cretaceous.
Dino eggs are found in certain regions:
It is a common misconception that dinosaur eggs have only recently been discovered. In fact, dinosaur eggs have been known for thousands of years. Dinosaur eggs have been described and reported world-wide, (See map) the first fully investigated discovery was in France in 1869.
Large advances have been made in the study of dinosaur eggs over the past twenty years. Once the eggs were a curiosity but dinosaur eggs are fast becoming a recognized subject of scientific study. However, this does not mean there is a huge amount of information on this subject. Dinosaur eggs are extremely rare, sightings are very rarely reported and the sites that are reported are not made publicly known. There are many myths surrounding dinosaur eggs. Consequently, they have been the subject of many misconception s by the public and the film industry, large dinosaurs have been assumed to have laid large eggs, however the largest egg to be discovered was no bigger than that of a football. Whilst scientists have worked on the identification of these eggs, their composition and structure, there has not been much evidence of research or theories of their implications. For example, if the eggs were large, patterned, strong or weak, were there reasons for this and what does this indicates about these animals. In addition the patterns of egg lying could be a major indication of the behaviour and social relationships of these animals. To evaluate the implications of egg structure and composition, it would be beneficial to look into the basic structures of eggs, site discoveries recent and old, nesting patterns and any behavioral traits.