Chapter 8 - The Application of Trace Fossils to Biostratigraphy

Abstract

Trace fossils are better known for their use in sedimentology and paleoecology than for their application in biostratigraphy. The characteristics that make trace fossils valuable in sedimentology and paleoecology limit their usefulness in biostratigraphy. However, in certain situations they can be the sole source of biostratigraphic data or can usefully augment biostratigraphic data from other sources. Trace fossils have been applied successfully to detailed biostratigraphy in the basal Cambrian (various ichnotaxa) and the Cambrian–Ordovician transition (trilobite traces, especially Cruziana), and to the dating of deep-marine Cambrian deposits (Oldhamia) and continental Mesozoic strata (vertebrate tracks). Other trace-fossil groups with potential biostratigraphic applications include certain complex, deep-marine traces (graphoglyptids), Tertiary insect-produced traces, and some bioerosion structures. Reliable trace-fossil biostratigraphy relies on high-caliber systematic ichnotaxonomy, augmented by careful paleoenvironmental analysis, and it can be conducted profitably in tandem with studies on the evolution of behavior. Invertebrate ichnofossils have proven especially helpful in Neoproterozoic and lower Paleozoic marine siliciclastic strata. Vertebrate trace fossils can be used to date and correlate Mesozoic continental strata. This chapter reviews the biostratigraphic advantages and limitations of trace fossils. It describes the main applications of trace fossils in biostratigraphy; briefly discusses other, potentially useful trace-fossil groups; and offers suggestions for optimal utilization of trace fossils as a tool in biostratigraphy.