Late Ordovician Paleontology, Sedimentology
and Stratigraphy in Ohio, Indiana and Kentucky
A Keck Geology Consortium Project
June 19 - July 16, 1999
In certain environments there are organisms which undergo rapid postmortem decay or dissolution and are rarely (perhaps never) represented in fossil assemblages. Lagerstatten are examples of where unique fossil preservation has occurs. One commonly overlooked process of preservation is bioimmuration, whereby soft-bodied organisms and those with aragonite shells are immured in the calcitic shells of others (Taylor 1990).
Bioimmurations are an incredible resource for research; however this study is not simply limited to just describing immured organisms. For example, if Ordovician bryozoans encrusted an aragonitic bivalve, then whether the bryozoans formed a cast or mold of the immured organism, the underside of the bryozoans would be exposed after bivalve dissolution. With their undersides now revealed, we can develop insight into ecological relationships (such as overgrowth and competition) not often seen in paleoecology.
My hypothesis is that repeatable ecological relationships exist
between types of hosts and encrusters, which reveal competition
between encrusters, and which depict a predictable succession
between encrusters. My hypothesis will also extend into looking
into the connection between types of hosts and succession of encrusters
in situations where there has been soft-bodied preservation. Results
derived from this working hypothesis will be directly connected
from paleontological relationships to ecological theory, offering
a valuable look not simply at bioimmuration phenomena, but also
at the ecology of encrusting processes.
