An unanswered ecological/paleocological question is "What is the relation between shelled animals living in soft-sediment benthic communities and the co-occurring (generally soft-bodied, mobile) infauna, and how this relationship changed through the Phanerozoic?" One possible, but largely untested, mechanism linking shelled and soft-bodied organisms is taphonomic inhibition), in which accumulation of dead hardparts negatively affects living animals. The goals of the project are to determine the impact of shell layers on an infaunal community inhabiting a modern sandflat and to evaluate whether or not shell layers exerted control over Ordovician infaunal animals. The project proposes a reasonable hypothesis for a possible interaction between shelled and soft-bodied animals, one that is testable in both modern and ancient communities. Shell layer inhibition of burrowing may help explain the typically disparate distribution of body and trace fossils, and may have been important in structuring soft-sediment benthic communities throughout the Phanerozoic.