Review on the thorax musculature in Odonata (Insecta), including the 3D-anatomy of adult Epiophlebiasuperstes.

Odonata comprises Anisoptera (dragonflies), Zygoptera (damselflies), and Epiophlebia, with Anisoptera and Epiophlebia forming the clade Epiprocta. Anisoptera exhibits robust bodies, dissimilar wing pairs, and eyes that may touch, while Zygoptera has slender bodies, uniform wings, and separated eyes; Epiophlebia, however, combines features of both, reflecting likely an ancestral condition. Detailed studies of odonatan thoracic musculature reveal differences between life stages and taxa, highlighting adaptations to larval aquatic and adult aerial lifestyles. This study revisited the thorax anatomy of Epiophlebia superstes to fill gaps in knowledge. High-resolution X-ray tomography was used to analyse, revealing 58 thoracic muscles: 17 in the prothorax, 20 in the mesothorax, and 21 in the metathorax. Comparison with previous studies confirmed the most known muscles, identified five new ones, and corrected earlier misinterpretations. Differences in muscle configurations among Odonata larvae and adults reflect their distinct ecological niches. Larvae generally possess more muscles, likely supporting their swimming and substrate-clinging activities. The generalised thorax model compiled findings from prior and current studies, simplifying the anatomy for comparative analysis with other insect groups. By enhancing understanding of Odonata thoracic anatomy, this research provides insights into the evolution of the insect flight apparatus, bridging knowledge gaps and aiding broader comparative studies.