Data from: Computational fluid dynamics confirms drag reduction associated with trilobite queuing behaviour

Queuing behaviour has been documented in marine arthropods from Cambrian
to modern oceans. One possible explanation of this behaviour is drag
reduction, with trilobites in the following positions hypothesized to
produce less drag than those leading. In this study, we evaluate the
hydrodynamics of queuing behaviour in the Devonian trilobite
Trimerocephalus chopini using computational fluid mechanics. Our results
show that the drag forces of the trilobites following in the queue were
substantially lower than those produced by the leader (75.1% lower at 2 cm
s-1). Drag reduction is positively correlated with the movement speed of
the trilobites, but decreases with increasing distance from the leader.
Our results support the hypothesis that the queuing behaviour of
trilobites was an adaptation for reducing hydrodynamic drag. This drag
reduction effect compensated for the energy cost of movement, which would
have been particularly advantageous during migration.

排队行为在从寒武纪到现代海洋的海洋节肢动物中均有记录。这种行为的一种可能解释是减阻效应，后续位置的三叶虫被假设产生的阻力小于领头个体。本研究采用计算流体力学（computational fluid mechanics）方法，评估了泥盆纪三叶虫Trimerocephalus chopini排队行为的流体动力学特性。结果表明，队列中后续三叶虫的阻力显著低于领头者（在2 cm/s速度下降低75.1%）。减阻效果与三叶虫的移动速度呈正相关，但随与领头者距离的增加而降低。本研究结果支持三叶虫排队行为是为降低流体动力学阻力而演化的适应性假说。这种减阻效应能够补偿移动的能量消耗，这在迁徙过程中尤为有利。