Unveiling the diversity of iron maiden ants: morphological insights from two new Cretaceous species

Abstract

The genus Zigrasimecia, also known as the iron maiden ant, represents a peculiar lineage spanning most of the Cretaceous period and characterized by armed mouthparts. Despite recent publications that have contributed to our understanding of the past diversity within this genus, its true extent remains underestimated and its morphological variations poorly comprehended. In this study, we introduce two new species of iron maiden ant, Zigrasimecia bellator sp. nov. and Zigrasimecia sinusoidal sp. nov. Using micro-computed tomography scanning and three-dimensional reconstruction techniques, we highlight their distinctive morphological features, particularly certain setae and microstructures of the body. Additionally, we present an updated identification key tailored for Zigrasimecia workers. Through comparative morphology, we propose hypotheses regarding the predatory behaviour of iron maiden ants. Our findings contribute to a deeper understanding of the morphological diversity within this fascinating ant genus.