Krista and I form the group that is primarily interested in the taphonomy of the dinosaur eggs. “What on earth is taphonomy?” most readers probably ask. Taphonomy means “the laws of burial” and is commonly understood to be all of the events and processes that act on an organism from the time of its death until the time of its discovery as a fossil. During the many millions of years that taphonomic processes act on an organism’s body, or in this case its eggs, much vital information concerning the body’s (or egg’s) appearance, chemical makeup, functioning, and place of death can be removed by any number of what we call taphonomic agents.
Common taphonomic agents whose actions can be readily observed today and that also acted in the past include scavengers (that destroy or remove bones and eggs) and streams (which can move, abrade, sort, and concentrate remains). Chemical and physical changes to the sediment surrounding the egg, as well as within the egg itself, are brought about during the transformation of loose sediment into rock over millions of years and have a profound impact on what information about the egg survives fossilization. This is why, for example, we rarely find fossils preserved in heavily altered and deformed metamorphic rocks.
What Krista and I are attempting to do is identify the ways in which the fossilized chunks of eggshell sitting on the worktable in front of us have been altered from their original shape, texture, microscopic structure, and arrangement within a clutch. Among other observations, we take largely qualitative data about the surface relief of the eggshell, its overall completeness, eggshell fracture patterns, and how the rock in contact with the eggshell differs from that found elsewhere. We do our best to keep in mind several working hypotheses, different scenarios that could produce exactly the same result, namely the fossil egg on the table in front of us.
It is our job as students of science to use all available evidence to sift through these working hypotheses, attempting to falsify each one until hopefully a clearer picture of the eggs’ taphonomic history comes into view.
One question that we are actively attempting to address is whether or not the purported “hatching window” (the opening in the egg through which a baby dinosaur would have emerged) can really be observed in the eggs.
Taphonomic data is incredibly important in any paleontological study because it helps to put specimens into their proper context, without which they would have very limited value to science. We work hand in hand with the sedimentology group to gain understanding of ancient environments and burial processes, in addition to working closely with the morphology group to inform hypotheses about what the eggs may have been like in life—a life that began and was cut short long before we arrived in Hangzhou, but also a life that will continue to challenge us long after we leave. — Danny Barta