Systematic and taxonomic revision of emerald and tigertail dragonflies (Anisoptera: Synthemistidae and Corduliidae)

Abstract Libelluloidea is the most species‐rich superfamily within dragonflies (Odonata: Anisoptera), yet intrafamilial relationships have remained contested for the past 150 years. Here we present a phylogenetic hypothesis for two families within Libelluloidea which together form a complex of distantly related lineages, Corduliidae s.l. (Emeralds) and Synthemistidae s.l. (Tigertails) based on comprehensive taxon sampling at species level (Corduliidae: 141/165 spp., Synthemistidae: 123/150 spp.) for which we generated anchored hybrid enrichment (AHE) high‐throughput molecular sequences (10–1054 loci). Furthermore, we combined our molecular dataset with 100 discrete morphological characters based on wing, body, nymphal and genital characters. Using our molecular data, and an evaluation of morphological characters via ancestral character state reconstruction, we propose a new classification for these taxa. Here, three new families are erected: Aeschnosomatidae fam. nov .; Lauromacromiidae fam. nov .; Macromidiidae fam. nov .; and the status is revised for six families: Austrocorduliidae Bechly, 1996 stat. rev .; Gomphomacromiidae Tillyard & Fraser, 1940 stat. rev .; Idionychidae Tillyard & Fraser, 1940 stat. rev .; Idomacromiidae Tillyard & Fraser, 1940 stat. rev .; Neophyidae Tillyard & Fraser, 1940 stat. rev .; and Pseudocorduliidae Lohmann, 1996 stat. rev . Furthermore, we synonymized Procordulia Martin, 1907, with the genus Hemicordulia Selys, 1870. Finally, we recover five enigmatic taxa ( Archaeophya Fraser, 1959, Libellulosoma Martin, 1907, Austrophya Tillyard, 1909, Apocordulia Watson, 1980 and Cordulisantosia Fleck & Costa, 2007) for which no molecular data was previously available within these families with revised status or new with high support using a total‐evidence approach. Character state reconstructions revealed widespread homology among traditional characters used to identify groups within each family. We estimate the ancestral Libelluloidea possessed an ovuloid anal loop, prominent uniform labial palp dentition in the nymphs and a reduced ovipositor. Finally, time‐divergence analyses estimate Libelluloidea to have originated within the Early Cretaceous, with subsequent families diversifying throughout the Cenozoic.