Borings in Cloudina Shells: Complex Predator-Prey Dynamics in the Terminal Neoproterozoic

Abstract

Abstract Predation as an important driver of evolutionary change long has been assumed, despite difficulties to substantiate it with specific examples of predatory interaction, especially for the early Paleozoic diversification of animal life. This study corroborates the existence of shell-drilling predation in the uppermost Neoproterozoic of China. Nearly one-fifth of almost one hundred tubular shells of one of the earliest mineralized animals, Cloudina, are perforated by undoubted predatory borings 15–85 µm wide. By contrast, no specimens of co-occurring shells belonging to Sinotubulites were affected. The identity of the predator remains elusive, but variation in size of the borings suggests a predatory lifestyle throughout its growth, after it reached a minimum size. The relatively uniform distance of the borings from the shell apertures points to either control by the life orientation of the shells, such as the position of the sediment surface, or, more likely, an avoidance response by the predator t...