THE CLASSIFICATION OF DINOSAUR EGGS BASED ON LITHOLOGICAL AND SHELL STRUCTURE ANALYSIS

Eight dinosaur eggs were donated to the James Madison University geology department. Based on the information provided by the donor, they are assumed to have come from China or Mongolia. Analyses of the eggs consisted of a general dimensional analysis, MRI (magnetic resonance imaging) at a nearby hospital (Rockingham Memorial Hospital), examining the shell structure and the lithifying material with a SEM and thin section analysis with a petrographic microscope.

The initial analysis of the eggs’ dimensions suggested that they were laid by a Therezinosaur, but this theory was later rejected based on analysis of the shell structure. A Therezinosaur egg would have a ratite morphotype, but the eggs have either a dendrospherulitic or angustispherulitic shell morphotype. The shell structure contains radiating segments with laminations within the segments and an upper, surface layer with massive structure.

Analysis of the surrounding matrix showed that the eggs were probably lithified in a sandstone unit. The matrix consisted predominantly of quartz and the grains are angular to subangular. The red color of the lithifying material suggests the presence of iron.

In order to determine where the eggs originated, the next step will be to acquire geologic maps of China and Mongolia to identify all sandstone units that are known to contain dinosaur eggs. The list of possible formations of deposition contained within the time range in which the geologic units were deposited will be cross-referenced with members of both the dendrospherulitic and angustispherulitic morphotype. The dinosaur families with that eggshell morphotype that lived in the region that is now China and Mongolia at the time of the units’ deposition will then be reviewed and listed as possible parents for the dinosaur eggs.