BURROWS AND ICHNOFABRIC PRODUCED BY CENTIPEDES: MODERN AND ANCIENT EXAMPLES

摘要

Centipedes extend to the Silurian yet have a relatively poor fossil record. Many species of extant centipedes are semi-fossorial to fossorial and contribute to soil processes, suggesting that their trace fossils should be common in paleosols. The goal of this project was to document the types of biogenic structures produced by two species of large, semi-fossorial centipedes, Hemiscolopendra marginal, and Scolopendra polymorpha, to aid in the recognition of fossil centipede burrows. Ten specimens of each species were placed in large, sediment-filled terrariums and observed over periods of 14 days. The centipedes burrowed via intrusion, compression, and excavation, moving throughout the enclosure both near the surface and deep within the sediment. Open burrows produced by the centipedes were cast with plaster and the ichnofabric produced was observed through the enclosure walls. The centipedes primarily produced J-, U-, and V-shaped burrows as well as complexes of linked burrows. The burrows were elliptical in cross section and possessed thin, intermittent, compressional linings. The centipede burrows were compared to burrows of other extant soil arthropods including millipedes, spiders, and scorpions as well as Pennsylvanian to Permian ichnofossils. The centipede burrows were distinct from those of other soil arthropods and many aspects of the ichnofossils were similar to those produced by the centipedes. Description of burrows 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 poor preservation potential of centipedes in the environments they inhabit.