Author Correction: Collective behaviour in 480-million-year-old trilobite arthropods from Morocco

Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Figure 1

Two non-exclusive hypotheses to explain the linear clusters of Ampyx priscus from the Lower Ordovician of Morocco. (a–c) Response to oriented environmental stress (e.g. storms); hydrodynamic signal (higher current velocity represented by white arrows) received by motion sensors triggers re-orientation of individuals; mechanical stimulation (small green circles) and/or possible chemical signals cause gathering, alignment and locomotion in group. (d–f) Seasonal reproductive behaviour; chemical signals (e.g. pheromones; see red circles and red arrows) cause attraction and gathering of sexually receptive individuals (males and females) and migration to spawning grounds. The alignment of individual may have been controlled by mechanical stimuli (as in a–c). Olfactive and mechanical sensors were probably located on the antennules (pink areas 1, 2), and genal and glabellar spines (green areas 3–5), respectively. The exact location of mechanoreceptors is uncertain (possibly on high-relief exoskeletal features such as the glabella).