Meridaphes Jałoszyński

Jałoszyński, Paweł, 2019, Taxonomy of the ' Afroeudesis group' of glandulariine ant-like stone beetles (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4612 (2), pp. 205-220 : 208-209

Meridaphes Jałoszyński

Meridaphes Jałoszyński, 2015c: 258 . Type species: Scydmoraphes venezolanus Franz, 1988 (orig. des.).

Revised diagnosis. Body (Fig. 1) moderately stout, distinctly constricted between head and prothorax and between prothorax and elytra. Head ( Fig. 9 ) indistinctly elongate with tempora subequal to eyes; tempora, vertex, genae and postgenae lacking thick bristles; occipital constriction only slightly narrower than vertex; submentum lacking lateral sutures; hypostomal ridges present and complete, obliquely running toward posterior tentorial pits where they are not connected; antennae gradually thickened; frontal and posteromedian impressions absent; longitudinal groove and median subtriangular 'platform' absent; frons and vertex with symmetrical setae ( Fig. 9 ; most setae are broken off, only setal sockets can be seen); maxillary palpomere IV constricted before apex, so that its apical portion is broadened and truncate; pronotum broadest in front of middle, with one pair of faint and diffuse lateral antebasal pits connected by a transverse groove, sides with lateral edges developed in posterior third and with faint sublateral carinae; sides of pronotum with dense bristles; prosternum with basisternal part as long as about half length of coxal part; prosternal intercoxal process developed as a diffuse ridge; procoxal cavities closed; notosternal sutures and hypomeral ridges complete; mesoscutellum largely exposed between elytral bases; mesocoxal rests with their posterior margins lacking carina or ridge; mesoventral intercoxal process carinate and strongly elevated, narrowly separating mesocoxae, with distinctly broadened, flattened and smooth median area, well-defined posterior tip and a shallow but distinct posteromedian notch; metaventral carinae absent; anterior metaventral process present, welldefined, conspicuously large, with subrectangular anterior tip and broadly triangular base; metaventral intercoxal process not separating metacoxae, subtriangular with shallow median notch, lacking lateral spines; each elytron with two vestigial asetose foveae; and aedeagus symmetrical with free, slender parameres.

Remarks. Morphological structures of Meridaphes were illustrated and a detailed description given by Jałoszyński (2015c). As nearly all setae on the head are broken off in the studied type specimen, the symmetrical pattern passed unnoticed at the time of describing this genus and revising its sole species, M. venezolanus . A reexamination of the same specimen allowed for identifying a symmetrical pattern of many setal insertion sites ( Fig. 9 ). Meridaphes shares most characters with Pseudoraphes ; it is also very similar to Stenichnoconnus . Meridaphes differs from both of them in the lack of the median longitudinal groove on the frons and vertex (such a groove, although diffuse, is present in Stenichnoconnus and Pseudoraphes ); the lateral clypeal margins divergent anterad (parallel in Stenichnoconnus and Pseudoraphes ); the pronotum lacking the outer pair of lateral pronotal pits (present in Stenichnoconnus and Pseudoraphes ); the posterior margins of mesocoxal rests not carinate (carinate in Stenichnoconnus and Pseudoraphes ); and the metaventral carinae absent (present in Stenichnoconnus and Pseudoraphes ). Moreover, Meridaphes differs from Stenichnoconnus in distinct, rounded tempora (vestigial in Stenichnoconnus ), the lack of the posteromedian impression on the vertex (present in Stenichnoconnus ), the pronotum broadest clearly in front of middle (behind middle in Stenichnoconnus ), the lateral and sublateral pronotal carinae present (absent in Stenichnoconnus ), and the lack of long lateral spines of the metaventral intercoxal process (present in Stenichnoconnus ). All these differences seem rather minor, but in a preliminary phylogenetic analysis of the genera of Glandulariini Meridaphes was not placed as sister to Pseudoraphes , but to all remaining components

of the ' Afroeudesis group' (Jałoszyński, unpublished). For this reason, the separate placement of Meridaphes is here maintained, pending further study.

Composition and distribution. Meridaphes comprises only one species, M. venezolanus , known to occur in Venezuela ( Fig. 41 ).

Figures

FIGURE 41. Distribution of 'Afroeudesis group'.

FIGURES 9–12. Examples of the symmetrical setal pattern on frons and vertex in representatives of the 'Afroeudesis lineage' (insertions of setae, including those broken off, marked by circles).Meridaphes venezolanus (9); Stenichnoconnus huijbregtsensis (10); Pseudoraphes minor (11); Afroeudesis (Nanoscydmus) baoshana (12).