Abstract
Soils contain complex ecosystems with a diverse micro- and macrofauna including arthropod predators. Our knowledge of arthropod predators in ancient soil ecosystems, however, is limited. This project involved the laboratory study of Mastigoproctus giganteus, or giant whip scorpion, to describe its burrowing behaviors and resulting burrow morphologies to aid the recognition of their burrows in the fossil record. Specimens were placed in sediment-filled terrariums for 14–60 days. Experiments were run with variations in sediment density and moisture to evaluate the effects of environmental conditions. The burrows were cast, described qualitatively and quantitatively, and then compared to each other and to scorpion burrows using nonparametric statistical methods. Six different burrow architectures were produced by the whip scorpions including vertical shafts, subvertical ramps, J-, U-, and Y-shaped burrows, and mazeworks. Despite these different architectures, the whip scorpion burrows possessed statistically similar properties that allowed them to be distinguished from burrows produced by scorpions. Sediment density and moisture had little influence on burrow properties but did affect the diversity of architectures produced. The greatest diversity of burrow architectures occurred in low-density sediment with moderate moisture levels. Results from this study show that whip scorpions produce unique biogenic structures possessing architectural and surficial properties that can be used to distinguish them from the burrows of other soil organisms. Data collected from these and similar experiments can be applied to ichnofossil assemblages found in middle Paleozoic to Pleistocene paleosols in order to better interpret the paleobiology and paleoecology of ancient soil ecosystems.
