ICHNOFABRIC PRODUCED BY CENTIPEDES: MODERN AND ANCIENT EXAMPLES

Centipedes have a body fossil record that extends to the Silurian. Centipedes have filled an important niche in ancient and modern soil ecosystems as invertebrate predators in environments ranging from rainforests to deserts. Many species of centipedes are semi-fossorial to fossorial and contribute to soil processes. As a result of their movement through the soil, centipedes produce a variety of biogenic structures ranging from disrupted soil fabric to discrete, open burrows. The morphology of these structures, however, is not well understood.

The goal of this project was to document the types of biogenic structures produced by two species of large, semi-fossorial centipedes, Hemiscolopendra marginata and Scolopendra polymorpha. Multiple specimens of these centipedes were placed in large, sediment-filled terrariums and observed over periods of 10-30 days. Both species entered the substrate through intrusion and moved throughout the enclosure both near the surface of and deep within the sediment. Open burrows produced by the centipedes were cast with plaster and ichnofabric was observed by cutting serial sections through the sediment. The morphology of the traces produced were described qualitatively and quantitatively. Biogenic structures produced in the laboratory were compared to ichnofossils collected from the Pennsylvanian to Permian Conemaugh, Monongahela, and Dunkard groups of Ohio and West Virginia. Many aspects of the ichnofabric observed in thin sections from these units was similar to that produced by the centipedes.

The description of the biogenic structures produced by centipedes can aid in the interpretation of continental ichnofossils and improve our understanding of the composition of ancient soil ecosystems. This knowledge is especially important given the relatively poor preservation potential of centipedes in the environments they inhabit. The ability to attribute specific ichnofossils to centipedes can improve our understanding of the geographic distribution of centipedes through time as well as their response to changes in soil environments.