Redefining the damselfly families: a comprehensive molecular phylogeny of Z ygoptera ( O donata)

An extensive molecular phylogenetic reconstruction of the suborder Z ygoptera of the O donata is presented, based on mitochondrial ( 16S , COI ) and nuclear ( 28S ) data of 59% of the 310 genera recognized and all (suspected) families except the monotypic H emiphlebiidae. A partial reclassification is proposed, incorporating morphological characters. Many traditional families are recovered as monophyletic, but reorganization of the superfamily C oenagrionoidea into three families is proposed: I sostictidae, P latycnemididae and C oenagrionidae. Archboldargia L ieftinck, Hylaeargia L ieftinck, Palaiargia F örster, Papuargia L ieftinck and Onychargia S elys are transferred from C oenagrionidae to P latycnemididae, and Leptocnemis S elys, Oreocnemis P inhey and Thaumatagrion L ieftinck from P latycnemididae to C oenagrionidae. Each geographically well‐defined clade of P latycnemididae is recognized as a subfamily, and thus D isparoneurinae (i.e. O ld W orld ‘ P rotoneuridae’) is incorporated, C alicnemiinae is restricted, and A llocnemidinae (type genus: Allocnemis S elys) subfam.n ., I diocnemidinae (type genus: Idiocnemis S elys) subfam.n . and O nychargiinae (type genus: Onychargia S elys) subfam.n . and C operini trib.n . (type genus: Copera K irby) are described. Half of C oenagrionidae belongs to a well‐supported clade incorporating Coenagrion K irby and the potential subfamilies A griocnemidinae, I schnurinae and P seudagrioninae. The remainder is less well defined, but includes the P seudostigmatidae and N ew W orld P rotoneuridae that, with A rgiinae and T einobasinae, may prove valid subfamilies with further evidence. Ninety‐two per cent of the genera formerly included in the polyphyletic A mphipterygidae and M egapodagrionidae were studied. Pentaphlebiidae, R imanellidae and D evadattidae fam.n . (type genus: Devadatta K irby) are separated from A mphipterygidae, and A rgiolestidae, H eteragrionidae, H ypolestidae, P hilogeniidae, P hilosinidae and T haumatoneuridae from M egapodagrionidae. Eight further groups formerly placed in the latter are identified, but are retained as incertae sedis ; the validity of L estoideidae, P hilogangidae and P seudolestidae is confirmed. For some families (e.g. C alopterygidae, C hlorocyphidae) a further subdivision is possible; P rotostictinae subfam.n . (type genus: Protosticta S elys) is introduced in P latystictidae. Numerous new combinations are proposed in the S upporting I nformation. Many long‐established families lack strong morphological apomorphies. In particular, venation is incongruent with molecular results, stressing the need to review fossil O donata taxonomy: once defined by the reduction of the anal vein, P rotoneuridae dissolves completely into six clades from five families.