Burmadysagrionidae Zheng et al., 2016

Bechly, Günter & Velten, Jürgen, 2023, A Revised Diagnosis of Palaeodysagrion cretacicus Zheng et al., 2016 (Insecta: Odonata) from mid-Cretaceous Burmese Amber, with erection of a new genus of fossil damselflies, Zootaxa 5263 (4), pp. 547-556 : 549

Family Burmadysagrionidae Zheng et al., 2016 stat. nov.

Comment. We concur with Archibald et al. (2021) and Archibald & Cannings (2021), against Nel & Zheng (2021) and Nel & Jouault (2022), that the five “dysagrionid” taxa from Burmese amber (i.e., Burmadysagrion Zheng et al., 2016 , Electrodysagrion Zheng et al., 2017 , Palaeodysagrion , and possibly Pseudopalaeodysagrion gen. nov.) do not belong in Dysagrionidae , but to a separate clade of zygopterid damselflies. The main reason is that the alternative explanation of the very different head structures with a diagenetic artefact seems highly implausible, given the number of different taxa from different localities that show no diagenetic distortions in any other parts of the body or the wings. Based on the results of the cladistic analysis of Archibald et al. (2021), we here elevate the subfamily Burmadysagrioninae erected by Zheng et al. (2016b) to the status of a family separate from Dysagrionidae , to include all all four genera. While Dysagrionidae belong to the suborder Cephalozygoptera , Burmadysagrionidae are closer to genuine Zygoptera .

Revised diagnosis. We consider the diagnosis of Burmadysagrioninae by Zheng et al. (2016b) as invalid because it includes numerous characters that are only known from Burmadysagrion zhangi Zheng et al., 2016 but not the other four species. Therefore, we tentatively suggest the following new diagnosis: dysagrionid-like wing venation, but zygopteroid transverse head (vs globular head in Dysagrionidae ); ax2 aligned with arculus in forewing but somewhat distal of arculus in hind wing (except in Pseudopalaeodysagrion youlini , and only very slightly so in Electrodysagrion ); pterostigma with basal side of normal obliquity (vs very oblique in Dysagrionidae ); pterostigma short and only covering a single cell (vs numerous cells in Dysagrionidae ) (except in Palaeodysagrion cretacicus which has 3 cells); CuA straight and with a single row of cells in cubito-anal space (vs CuA curved and with several rows of cells in cubito-anal space in Dysagrionidae ).