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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.
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