Meridaphes Jałoszyński, 2015, gen. nov.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Meridaphes

description: Meridaphes gen. nov.
Type species: Scydmoraphes venezolanus Franz, 1988: 63 (here designated).
Diagnosis. Among Neotropical Cyrtoscydmini, Meridaphes is the only genus with anterior metaventral process at base as broad as about 1/3 of metaventral width and strongly narrowing anteriorly to form subrectangular apex which meets the posterior tip of mesoventral intercoxal process, which is strongly broadened in the intermesocoxal region. Additional diagnostic characters comprise: head elongate with tempora longer than eyes, without lateral bristles; occipital constriction about as broad as frons between eyes; submentum lacking lateral sutures; hypostomal ridges present and posteriorly reaching level of posterior tentorial pits; antennae gradually thickened distally; pronotum with transverse antebasal groove connecting faint lateral impressions and with lateral edges developed in posterior third or fourth of PL; sides of pronotum with dense bristles; prosternum with basisternal part as long as about half length of coxal part; prosternal intercoxal process indistinct, diffused; procoxal sockets broadly closed; notosternal sutures and hypomeral ridges complete; prosternum entirely demarcated from hypomera; mesothorax with ventrolateral foveae; metaventral intercoxal process not separating metacoxae, subtriangular with shallow median notch; each elytron with two barely discernible rudiments of asetose foveae; and symmetrical aedeagus with slender parameres.
Description. Body of male (Fig. 9) strongly convex, moderately slender, with moderately long appendages, BL slightly exceeding 1 mm; cuticle glossy, brown, sparsely setose.
Head (Figs 10, 12, 17–18) slightly elongate and approximately subtrapezoidal, with small eyes; occipital constriction (Fig. 17; occ) in the narrowest place about as broad as frons between eyes; 'neck' region (Fig. 17; nr) much broader than long, nearly as broad as vertex; tempora longer than eyes and strongly rounded; vertex strongly transverse; frons posteriorly confluent with vertex, subtrapezoidal, anteriorly not projecting at middle; frontoclypeal groove absent; antennal insertions broadly separated. Tempora and posterior margin of vertex lacking bristles.
Labrum (Fig. 17; lb) transverse with rounded anterior margin. Each mandible (Figs 13, 17–18; md) subtriangular, with broad and blunt subapical mesal tooth; basal mesal region not visible in studied specimens. Each maxilla with short and broad cardo (Figs 13, 18; cd), subtriangular basistipes (Figs 13, 18; bst), short mediostipes (Figs 13, 18; mst) and elongate galea (Figs 13, 18; gal) and lacinia, each with dense setae along distomesal margin, maxillary palp (Figs 12, 18; mxp) moderately long, palpomere I small but strongly elongate, palpomere II strongly elongate, nearly pipe-shaped, palpomere III large and elongate, broadest near distal third, palpomere IV subconical with slightly thickened apex. Labium with broad submentum (Figs 13, 18; smn) not demarcated laterally by sutures; subtrapezoidal mentum (Figs 13, 18; mn) and short prementum, ligula indistinct, bearing pair of bristles; labial palps (Figs 13, 18; lp) short, moderately broadly separated at bases, with palpomere II relatively long. Hypostomal ridges (Figs 12, 18; hy) distinct and recurved, posteriorly reaching posterior tentorial pits.
Gular plate (Figs 12, 18; gp) broadly subtrapezoidal with rounded sides, gular sutures (Figs 12, 18; gs) superficial. Posterior tentorial pits (Figs 12, 18; ptp) exposed, arcuate, located in front of transverse impression demarcating 'neck' region.
Antennae (Fig. 9) gradually thickening distally.
Pronotum in dorsal view (Fig. 9) elongate subtrapezoidal, anterior margin and sides in anterior half rounded, anterior corners indistinct, obtuse-angled, and blunt, sides in posterior half weakly narrowing toward distinct and nearly right-angled posterior corners; posterior margin shallowly bisinuate. Pronotum with lateral edges developed in posterior third or less, with distinct transverse antebasal groove connecting faint lateral impressions. Sides of pronotum with dense bristles.
Prosternum (Figs 14, 19) with basisternal part (Fig. 19; bst) indistinctly demarcated from coxal part and much shorter than the latter; prosternal intercoxal process (Fig. 19; psp) feebly marked as narrow and weakly elevated carina with diffused lateral margins; procoxal sockets (Fig. 19; pcs) broadly closed. Notosternal sutures (Fig. 19; nss) and hypomeral ridges (Fig. 19; hyr) complete.
Mesoscutellum visible between elytral bases, broadly subtriangular with elongate and rounded posterior part and concave lateral margins; mesoscutoscutellar suture present.
Mesoventrite (Figs 15–16, 20) with distinct anterior ridge (Figs 15–16, 20; ar) and long, carinate and strongly elevated mesoventral intercoxal process (Figs 15–16, 20; msvp) extending from just behind anterior ridge of mesoventrite to middle of mesocoxae, where it is distinctly broadened and flattened ventrally. Ventrolateral foveae (Fig. 20; vlf) present. Mesocoxal projections (Fig. 20; mcp) prominent, with mesocoxal sockets located on their mesoventral surface and exposed in ventral view. Mesoventrite with narrow and shallow asetose pair of procoxal rests (Figs 15–16, 20; pcr); area behind procoxal rests asetose and not impressed.
Metaventrite (Figs 16, 20; v3) subtrapezoidal, broadening posteriorly and with rounded sides; anterior metaventral process (Figs 15–16, 20; amvp) present and strikingly large, with base as broad as about 1/3 of metaventral width and subtriangular in shape, with subrectangular anterior tip meeting posterior tip of mesoventral intercoxal process, sides of anterior metaventral process densely setose. Metaventral intercoxal process (Figs 15– 16, 20; mtvp) not separating metacoxa, subtriangular with shallow median notch. Metanepisterna and metepimera narrow. Metendosternite (metafurca) not visible in studied specimens.
Elytra (Fig. 9) oval, each with two barely discernible rudiments of asetose basal foveae.
Legs (Fig. 9) moderately long and slender; pro- and mesocoxae oval, metacoxae transverse; all femora weakly and gradually clavate (profemora thickest), all tibiae slender and nearly straight, broadening distally, protibiae thicker than meso- and metatibiae and with apical denticle; tarsi short and robust.
Abdominal sternites unmodified, suture between two terminal sternites indistinct.
Aedeagus (Figs 10, 25–26) stout, drop-shaped with truncate apex of median lobe, median lobe symmetrical, endophallus nearly symmetrical; internal armature complicated, composed of elongate sclerites surrounding median longitudinal tubular component; parameres present, moderately slender and with apical setae.
Distribution and composition. Only one species of Meridaphes is known, occurring in Venezuela.
Etymology. The name Meridaphes is composed of the Venezuelan Mérida State's name and - phes, a common ending of names in Scydmaeninae. Gender masculine.
Remarks. The following characters clearly indicate that Scydmoraphes venezolanus is not congeneric with Northern Hemisphere Scydmoraphes: submentum lacking lateral sutures (present in Scydmoraphes); posterior tentorial pits exposed (hidden in deep transverse groove demarcating 'neck' region in Scydmoraphes); eyes distant from occipital constriction and tempora long (eyes close to occipital constriction and tempora very short in Scydmoraphes); mesoventral intercoxal process strongly elevated, with well-defined anterior tip and strongly broadened between mesocoxae (weakly elevated, lacking anterior tip and between mesocoxae narrowing to subtriangular rounded tip in Scydmoraphes); anterior metaventral process extremely broad and subtriangular, at base as broad as about 1/3 of metaventral width, with subrectangular anterior tip (process short and narrow, subrectangular in Scydmoraphes); and each elytron with two barely discernible (even in transparent mount) rudiments of basal foveae (single distinct and deep fovea in Scydmoraphes). Moreover, Sc. venezolanus has distinctly swollen maxillary palpomere III, which is slender in Scydmoraphes.
Although the strongly elevated, keel-like mesoventral intercoxal process of Meridaphes is similar to that in Euconnus, Meridaphes differs from Euconnus in several important characters: broad occipital constriction (much narrower in Euconnus); gular plate lacking elongate anterior part (demarcated, anterior part present in Euconnus); absent frontoclypeal groove (present in Euconnus); pronotum with short posterolateral edges (lacking edges, but often with sublateral carinae in Euconnus); presence of large, subtriangular anterior metaventral process (absent in Euconnus); and contiguous metacoxae (distinctly separated in Euconnus). The extremely broad, subtriangular anterior metaventral process is known only in the eastern Palaearctic genus Nanoscydmus Jałoszyński, 2009.
Besides clearly different body form, Nanoscydmus has the frons and vertex with median longitudinal groove and triangular raised area demarcated by distinct edges (entirely lacking in Meridaphes), prosternum laterally demarcated from hypomera by complete notosternal sutures (prosternum laterally fused with hypomera and notosternal sutures internalized, not marked externally in Nanoscydmus); mesoventral intercoxal process strongly broadened between mesocoxae (evenly narrowing posteriorly in Nanoscydmus); and metaventral intercoxal process without spines (with a pair of long spines in Nanoscydmus).
description: Published as part of Jałoszyński, Paweł, 2015, Revision of Neotropical species of ant-like stone beetles misplaced in Stenichnus and Scydmoraphes (Coleoptera, Staphylinidae, Scydmaeninae), pp. 253-269 in Zootaxa 4027 (2) on pages 258-261, DOI: 10.11646/zootaxa.4027.2.5, http://zenodo.org/record/243788