Macromiidae

The Macromiidae is a relatively small family comprising 4 genera and 126 species (Paulson et al. (Coordinators), World Odonata List, Odonata Central. University of Alabama, 2023. https://www.odonatacentral.org/app/#/wol/. Accessed 18 July 2023), distributed throughout the world except the Neotropical region. Adult macromiids patrol the shorelines of lakes, ponds, and streams; the nymphs live in various substrates partially hidden in soft beds of mud, silt, or sand or among root mats. Two genera occur in Thailand: Epophthalmia with 2 species and the more diverse Macromia with 13 species known and 6 more yet to be described; both genera are widely distributed throughout the country. Nymphs of Epophthalmia are distinguished from those of Macromia primarily by the condition of the labial palp, which is strongly developed, moderately reflexed, and lacking setae, and the distal margin has 6–7 strong, hook-like, asymmetrically developed teeth; in addition, premental setae are absent, and the ligula is biconvex. The macromiids were long considered as belonging to the family Corduliidae, or even as a subfamily of Libellulidae, but recent phylogenetic studies based on morphological and molecular analyses consider macromiids to be monophyletic and the sister group of Corduliidae.