The cephalo-thoracic apparatus of Caputoraptor elegans may have been used to squeeze prey

Abstract

Alienoptera is an insect order recently described from mid-Cretaceous amber [1] and is phylogenetically nested in the Dictyoptera lineage. Alienoptera currently comprises three species: Alienopterus brachyelytrus[1], Alienopterella stigmatica[2] and Caputoraptor elegans[3]. The most interesting is Caputoraptor elegans, which was recently described in Current Biology by Bai and colleagues [3] and which has an unusual cephalo-thoracic device formed by wing-like extensions of the genae and the corresponding edges of the pronotum. Bai and colleagues [3] suggested that the cephalo-thoracic apparatus may have been used to hold the female and male together during copulation. According to this possible function, the cephalo-thoracic apparatus of the female would fit together with the spread forewings of the male while the female was on the back of the male during copulation. This function was proposed based on examination of females and nymphs, and the authors stated that it could be falsified if a male with a similar apparatus were discovered. After examining a male nymph of this species (Figure 1), I here suggest that the cephalo-thoracic apparatus was not used for copulation but was instead used for predation and feeding.