Geoscience Reference
In-Depth Information
ing floods could have arranged the eggs in clusters like those we
found in the quarry.
The number of eggs in a clutch also varies among modern egg-
laying animals. The number usually correlates with the amount of
food available during the nesting season, along with the abundance of
parasites and predators. Ostriches usually lay between fifteen and
thirty eggs; crocodiles are known to lay up to sixty eggs; and Komodo
dragons tend to lay between twenty and thirty eggs. Thus, the large
number of eggs in our clutches was not surprising. What was sur-
prising, however, was that the number of eggs in a typical clutch was
much larger than the number documented in suspected sauropod
nests at other sites around the world, where there are usually less than
ten eggs in a megaloolithid nest. Perhaps this significant difference
reflects an abundance of food at Auca Mahuevo, a possibility that is
also suggested by the immensity of the nesting colony.
The 3-D map also documented two separate egg layers in the
quarry, separated by a few inches of mudstone, which suggested that
This three-dimensional map of eggs from layer 3 at Auca Mahuevo shows how
these eggs are generally clustered in distinct clutches. The vertical scale of this
diagram has been exaggerated to show better the existence of two levels of
eggs, whose separation is depicted here by the intervening light gray plane.
