Locomotion and feeding trails produced by crabs

Abstract

Trace fossils represent the biological activity of an organism in the form of trails, tracks, burrows, and borings in the geological record. Bilobate trails are known to be made by arthropod trilobites since the Early Palaeozoic. This study enhances the present state of knowledge regarding bilobate trails by demonstrating that they can also be produced by crabs reflecting different behavioural traits such as different feeding and locomotion strategies. This present‐day study thus warns caution to be taken when linking horizontal trails such as Archaeonassa and Diplopodichnus with tracemakers in Jurassic strata and onwards since crabs have existed. Identifying crab‐related trace fossils might be particularly insightful for understanding the earliest evolution of Jurassic crabs for which dorsal carapaces are dominantly the only form of preservation.