Onthophagus brittoni Paulian, 1948

[Figs. 22 – 26]

Onthophagus brittoni Paulian, 1948: 148; Paulian 1980: 153; Zunino 1980: 413; Löbl et al. 2006:173; Krajcik 2012: 176; Ziani & Bezdĕk 2016: 201.

Type locality. “ Western Aden Protectorate, Dhala ” [Yemen].

Type material examined. Holotype, male, fixed by original designation (NHMUK).

Type labelling. 1 st, white [where specimen and edeagus are attached], handwritten in black: “ Onthophagus / brittoni / Paulian / TYPE.”; 2 nd, white, printed in black: “TAKEN AT LIGHT.”; 3 rd, circular, white and red, printed in black: “ Type / H. T.”; 4 th, white, printed in black: “W. ADEN PROT. / Dhala. / 4,800ft. / 14.ix.1937.”; 5 th, white, printed in black: “B. M. Exp. to / S. W. Arabia. / H. Scott & / E. B. Britton.”; 6 th, white, handwritten and printed in black: “ Onthophagus / brittoni n. sp. / R. Paulian det.”; 7 th, white, handwritten and printed in black: “ Onthophagus (Phanaeo.) / brittoni Paul. / J. SCHEUERN det. 98”.

Diagnostic features. Length 6.0 to 8.5 mm. Colour blackish-brown to black, moderately glossy, with distinct isodiametric microreticulation; antennal scape, pedicel and funicle dark yellow, antennal club yellow; setation pale yellow.

Male (Fig. 22). Head with clypeal margin medially fairly strongly prolonged into a round point, sinuated at sides and strongly reflexed upward; rest of head margin evenly round to genal angles, which are round; frons flat, without any carina or depression; occipital margin raised at middle into a single semi-circular slightly prominent tubercle, flanked by a small concave hollow on each side, close to the eye; all the surface densely, coarsely and regularly punctate, except the hollows, smooth.

Pronotum with two ridges converging anteriorly toward the middle and forming the upper anterior edge of the highly elevated disc, shaped like an isosceles triangle, with an anterolateral depression on either side; pronotal sides distinctly margined, not sinuate behind anterior angles; dorsal surface sub-regularly and densely punctate on disc, punctures separated by half to one their diameters, granulate at sides; each puncture bears a yellow seta, short on disc, longer at sides.

Elytral striae wide, their punctures crenating interstriae; the latter flat on disc; interstriae with irregular granules, each of them bearing a yellow seta.

Pygidium margined basally, setigerous punctate, punctures large, coarse, sub-regularly impressed, surface between punctures shining, clearly microreticulate.

Middle and hind femora ventrally with sparse setigerous punctures; foretibiae quadridentate externally; middle and hind tibiae short, triangular, broad apically; apical spur clearly longer than first segment of hind tarsi; middle and hind tarsi more or less widened and flat, the second to fourth tarsal joints differing only slightly in length.

Female (Fig. 23). Head with clypeal margin prolonged medially but not forming a round point; pronotal process weak, represented only by two anterolateral faint depressions; pronotal punctation smaller and sparser, punctures separated by one and half to two their diameters on disc.

Variability. As with most Onthophagini species, intraspecific variability stands in the degree of development of pronotal process: minor males have a like-female pronotum ornamentation. Furthermore, the colour of the body varies from dark brown to black.

Male genital armature. Parameres very short, sinuate laterally in dorsal view, with strong latero-apical spatulae bent ventrally, not divergent apically (Figs. 24 – 25); internal sac with some accessory lamellae and a comma-shaped lamina copulatrix with two counterposed arms (Fig. 26).