Euthygomphus schorri - also in Vietnam

Oleg Kosterin published a paper last year in which he tackled some of the problems surrounding the genus Anisogomphus and the genus Merogomphus. Part of the solution was to erect a new genus, Euthygomphus. In the process he also described a new species: Euthygomphus schorri. Now, in the spring of 2016 I had caught some gomphids near Bao Loc in Lam Dong Province that for the moment I considered Merogomphus parvus. Their true identity now became immediately apparent. This too is Euthygomphus schorri. Not surprising really. The location where I caught them abounds in species that have recently been described for Cambodia just across the border, but are new for the Vietnamese Odonate fauna. In this case the shape of the caudal appendages and vesicle spermalis are the give away characters to identify the species, as Euthygomphus species are otherwise confusingly similar in outward appearance. A check in hand or close-up photo is necessary to clinch the ID. The caudal appendages are curved outward in dorsal view and have a distinct upward apical tooth.
This is the third Euthygomphus species found in Vietnam. The others are E. koxingai and E. yunnanensis (formerly thought to be E. parvus).

I refer to Oleg's paper "Reconsideration of the genera Merogomphus Martin, 1904, and Anisogomphus Selys, 1857, including erection of a new genus, with a new species and discussion of addition specimens from Cambodia" in Zootaxa 4171(1):51-76 for the details concerning the identification of these species.

Male Euthygomphus schorri, near Bao Loc, Lam Dong Province, 12 June 2016

Same male at slightly different angle