Computational fluid dynamics confirms drag reduction associated with trilobite queuing behaviour

Queuing behaviour has been documented in marine arthropods from Cambrian to modern oceans. It was previously hypothesized that this provided energy savings through hydrodynamic drafting, with trilobites following positions produce less drag than those leading. In study, we evaluate the hydrodynamics of queuing Devonian trilobite Trimerocephalus chopini using computational fluid dynamics. The results show forces queue were substantially lower produced by leader (˜65–79% at velocities 0.5–2 cm s−1). Drag reduction positively correlated movement speed trilobites, but decreased increasing distance leader, and there essentially no all for first when greater about six times its body length. This agrees fossil evidence preserving queues close proximity each other. also still significant (˜86.8% 2 s−1) even longest preserved record. Our findings support hypothesis an adaptation reducing drag. effect compensated cost movement, which would have particularly advantageous during migration.