EXPERIMENTAL INVESTIGATION OF TERRESTRIAL BIOTURBATION

Investigation of the burrowing behavior and biogenic structures of extant terrestrial animals leads to an improved understanding of organism-substrate interactions and the preservation of organism behavior in the fossil record. Trace fossils provide a critically important in situ record of paleoenvironmental and paleoecological change that has become an essential tool in paleontology and sedimentary geology.

Simple laboratory experiments were designed to demonstrate to geology undergraduate and graduate students the methods of burrow construction, behavior recorded by burrows, architectural responses to environmental variations, and the preservation potential of burrows. Animals selected for this study included Sonoran Desert millipedes, Giant African millipedes, and Emperor scorpions. The animals were placed in substrate filled terrariums and observed over a 14 day period. Different animals were then subjected to variable experimental conditions including changes in substrate type, average temperature, and substrate moisture in order to represent a range of depositional settings.

Results from these experiments included the production of plaster casts of burrows whose architecture and surficial features were qualitatively and quantitatively described and related to the tracemaker and environment. This process helps students interpret trace fossil morphology as well as the means of their construction and preservation. These experiments provide a hands-on demonstration of the process of interpreting the fossil record using modern analogs.