Euconnus (Rhomboconnus) giraffa Sharp, 1887

Jałoszyński, Paweł, 2020, Euconnus (Rhomboconnus): redescriptions of species described by Schaufuss and Sharp, and descriptions of five new Mexican species (Coleoptera, Staphylinidae Scydmaeninae), Zootaxa 4759 (2), pp. 209-222 : 212-214

Euconnus (Rhomboconnus) giraffa Sharp

( Figs 2 , 10 , 17–18 , 24–28)

Euconnus giraffa Sharp, 1887: 52 ; Franz 1994: 340, 376 (misidentified, not E. giraffa !); Franz 1995: 69, 76, fig. 29 (misidentified, not E. giraffa !).

Euconnus (Scopophus) giraffa Sharp ; Franz 1994: 376 (misidentified, not E. giraffa !; assigned to Scopophus only in key).

Euconnus (s. str.) giraffa Sharp ; Csiki, 1919: 48.

Holotype: Guatemala: ♂ ( Fig. 2 ), mounted on thick cardboard ( Fig. 17 ) with handwritten “ Euconnus gi- / raffa. Type DS / San Juan Guat. / Champion”, and with five historical labels ( Fig. 18 ): “ B.C.A. Col. II. 1. / Euconnus / giraffa / Sharp.” [creamy white, printed], “San Juan, / Vera Paz. / Champion” [creamy white, printed], “7” [creamy white, handwritten], “Sharp Coll. / 1905.–313.” [creamy white, printed], “ SYNTYPE ” [circular, white with blue margin, printed]; during the present study a new label was added: “ EUCONNUS / ( RHOMBOCONNUS ) / giraffa / Sharp, 1887 / det P. Jałoszyński, 2020” [white, printed] ( NHM).

Emended diagnosis. Head in male relatively stout, with narrowly projecting and nearly straight posterior margin of vertex; tempora nearly straight; pronotum subtrapezoidal with rounded sides, slightly broader than long and broadest near middle, with sharply marked transverse antebasal groove indistinctly deepened at each end and poorly visible, short and diffuse sublateral carinae; dorsum sparsely setose; antennomeres VII–X elongate ( VII the longest); aedeagus with ventral plate in its subapical region indistinctly constricted; endophallus with long sclerites, of which the longest is pointed at apex, with asymmetrical distal half.

Redescription. Body of male ( Fig. 2 ) strongly convex, elongate, with moderately long and slender appendages, BL 2.65 mm; cuticle glossy, uniformly dark reddish-brown, vestiture yellowish.

Head ( Fig. 10 ) relatively short and small in relation to pronotum and elytra, strongly narrowing posteriorly, broadest at eyes, HL 0.58 mm, HW 0.50 mm; vertex and frons confluent and together evenly convex, posterior margin of vertex narrower than half HW and nearly straight; tempora about 3 × as long as eyes in dorsal view, nearly straight on entire length; supraantennal tubercles barely marked; eyes large, finely faceted and strongly projecting from silhouette of head. Punctures on vertex and frons very fine and inconspicuous; thin setae moderately long and sparse, suberect, median area of frons and vertex nearly asetose, additionally each temple with several slender tufts of thick and long bristles near occipital constriction. Antennae slender and long, AnL 1.53 mm; all antennomeres except III distinctly elongate (VII the longest), III about as long as broad; antennomeres X–XI indistinctly flattened, XI slightly shorter than IX–X together, about 2.2 × as long as broad.

Pronotum ( Fig. 10 ) in dorsal view nearly subtrapezoidal with rounded sides, broadest near middle, strongly narrowing anteriorly, PL 0.60 mm, PW 0.65 mm; sides strongly rounded, anterior and posterior margins nearly straight; base with two tiny lateral pits connected by sharply marked transverse groove, and with short, rounded and indistinct sublateral carinae slightly laterad each antebasal pit and extending from base to the level of transverse groove. Punctures inconspicuous; pronotal disc with sparse, moderately long suberect setae, sides with thick and long bristles.

Elytra together suboval, broadest distinctly in front of middle, EL 1.48 mm, EW 1.10 mm, EI 1.34; apices separately rounded. Punctures on elytral disc slightly more distinct than those on head and pronotum, but small, superficial and sparse, inconspicuous; elytra covered with moderately long suberect setae, which are predominantly directed posterolaterad and distinctly denser than those on head and pronotum

Legs moderately long and slender; unmodified.

Aedeagus (Figs 24–28) stout, AeL 0.55 mm, in ventral view drop-shaped and rapidly narrowed in subapical region; endophallus with a narrow complex of slender sclerites (Fig. 28), of which the longest is asymmetrical in apical region, with slender and pointed apex; parameres slender, each with three long apical and subapical setae.

Female. Unknown.

Distribution. Central Guatemala, Alta Verapaz Department.

Remarks. This species was treated as Euconnus s. str. by Csiki (1919), and either as Euconnus incertae sedis by Franz (1994, 1995), or as Euconnus (Scopophus) in the identification key of Franz (1994). However, Franz’s redescriptions and published records are entirely based on non-type specimens, which during the present study were recognized as not conspecific with the holotype of E. giraffa . Interestingly, Franz (1994, 1995) listed the holotype of E. giraffa among (presumably) studied specimens, yet the specimens he used to ‘redescribe’ this species (preserved in Franz Collection of NHMW) are so strikingly different from the Sharp’s type (much smaller, with the antennae much shorter in relation to body, with the head, pronotum and elytra of different shapes and proportions), that it seems highly implausible that Franz has ever seen the type material. Euconnus giraffa sensu Franz (1994: 340 ; 1995: 69) is described below as a new species; like the true E. giraffa , it also belongs to the subgenus Rhombocon- nus (placement supported by the unique structure of the head, including the ventral longitudinal groove, and the aedeagus).

Euconnus giraffa is a remarkable species that can be easily distinguished from all remaining members of Rhom- boconnus by its body form, especially the shape of pronotum (which is conspicuously broader than the head) and elytra weakly narrowing from the broadest site toward humeri.

Figures

FIGURES 1–8. Dorsal (1–3, 5–8) and lateral (4) habitus of Euconnus (Rhomboconnus). Euconnus cavifrons (L.W. Schaufuss) (1); E. giraffa Sharp (2); E. agiraffa sp. n. (3–4); E. oaxacanus sp. n. (5); E. bicarinatus sp. n. (6); E. cordobanus sp. n. (7); E. maya sp. n. (8).

FIGURES 9–15. Head and pronotum of Euconnus (Rhomboconnus) in dorsal view. Euconnus cavifrons (L.W. Schaufuss) (9); E. giraffa Sharp (10); E. agiraffa sp. n. (11); E. oaxacanus sp. n. (12); E. bicarinatus sp. n. (13); E. cordobanus sp. n. (14); E. maya sp. n. (15). Abbreviations: ami, anteromedian impression; abg, antebasal groove; abp, antebasal pit; slc, sublateral carina.

FIGURES 16–18. Historical sets of labels (16, 18) and original mounting card of type specimen (17). Euconnus cavifrons (L.W. Schaufuss) (16); E. giraffa Sharp (17–18).