Otostigmus (Parotostigmus) volcanus Chamberlin, 1955

Chagas-Jr, Amazonas & Souza, Emerson Marques, 2024, A review of the types of some Otostigmus (Parotostigmus) (Scolopendromorpha, Scolopendridae, Otostigminae) of the Andes mountain range, Zootaxa 5529 (3), pp. 436-460 : 455-456

Otostigmus (Parotostigmus) volcanus Chamberlin, 1955 syn. nov.

Figs 47–51

Type material examined: Holotype CAS 9188 (597-7770), Argentina, Jujuy, 3 mi. S. Volcan Jujuy, 16.ii.1911, Ross and Michelbacher, 2000 m.

Redescription of holotype. Length: 40 mm from anterior margin of cephalic plate to posterior margin of tergite 21( Figs 47, 48 ). Antennae with 12 articles (right, damaged) and 13 (left, damaged) [17 articles]; first two basal and basal part of third glabrous. Cephalic plate smooth, without sutures and depressions, but with median sulcus [very short] in the anterior part (almost slightly concave) [not described] ( Fig. 49 ). Coxosternal tooth-plates wider than long, with 4+2 teeth (left plate is damaged), and a long bristle, not fused, only in the middle; coxosternite with a short paired sutures at base ( Fig. 50 ), this suture is bifurcate in the sides and a short median longitudinal suture. Trochanteroprefemoral process moderately large, with the margin with one short denticle and with the tip pointed [not described]. Tergites smooth. Tergites 6–19 with complete paramedian sutures [tergites 5–14]; tergites 2–5 with very short incomplete paramedian sutures [not described]; only tergite 21 margined; Posterior margin of tergite 21 very slightly angulate [convex] [with a shallow depression in posterior margin]. Sternites 3–19 with incomplete paramedian sutures [without sutures]; incomplete paramedian sutures from anterior and posterior sternites shorter than the sternites of middle body that almost reach ¾ of the sternite. Sternite 21 with posterior margin straight, slightly concave, shorter than precedent, trapezoidal, without depression ( Fig. 51 ). Coxopleuron without spines, with posterior part truncate with a very short protuberance. Pore-field covers almost entire coxopleuron, only the posterior end poreless. Right leg 1 without femoral and tibial spur, but left leg 1 with femoral and tibial spur; legs 1–5 with two tarsal spurs; legs 6–19 with one tarsal spur, 20 and 21 without. Prefemur of ultimate legs without spines. No sexual appendix, normal in shape.

Remarks. The holotype of O. volcanus syn. nov. is closely related with O. leior . Both O. volcanus syn. nov. and O. leior have only tergite 21 marginated, two tarsal spurs on walking legs 1–2 and a tarsal spur on legs 3–19. In addition, they share similar tergite characters such as complete paramedian sutures (tergites 6–20 in O. volcanus syn. nov. and 6–19 in O. leior ). Although O. volcanus syn. nov. and O. leior are closely related to O. muticus because the size of the body, the absence of a rounded depression on the sternites and the posterior margin of sternite, O. volcanus syn. nov. is closer to O. leior , therefore is considered a junior synonym of O. leior .

Figures

FIGURES 47–48. Otostigmus (P.) volcanus Chamberlin, 1955 syn. nov. Holotype CAS 9188 (597-7770). 47. General view dorsally. 48. General view ventrally.

FIGURES 49–51. Otostigmus (P.) volcanus Chamberlin, 1955 syn. nov. Holotype CAS 9188 (597-7770). 49. Cephalic plate and tergites 1 and 2, dorsally. 50. Head, forcipular segment, and sternites 1and 2, ventrally. 51. Sternites 19-21, ventrally.