Otostigmus (Parotostigmus) clavifer Chamberlin, 1921

Chagas-Jr, Amazonas, 2016, A systematic appraisal of the types of ten species of Otostigmus (Parotostigmus) (Scolopendromorpha, Scolopendridae, Otostigminae), Zootaxa 4147 (1), pp. 36-58 : 41-43

Otostigmus (Parotostigmus) clavifer Chamberlin, 1921

( Figures 11–14 )

Otostigmus clavifer Chamberlin, 1921: 13 , Pl. 1, Fig. 3 ;

Otostigmus (Parotostigmus) clavifer Attems, 1930: 165 ; Bücherl, 1974: 112; Otostigmus (Androstigmus) clavifer Bücherl, 1940: 223 ; 1942: 60;

Otostigmus (Parotostigmus) brunneus Chamberlin, 1921: 13 . Syn. nov. (see above)

Type material examined. Holotype MCZ IZ no. 2180 (14285), Guyana (British Guiana), Sand Hill Forest Expedition: Bryant Walker Expedition (Uni. of Michigan), 1914, F.M. Gaige, 24.viii.1914 ( Figs 11–12 ).

Diagnosis. Tergites smooth. Sternites 2–20 with short incomplete paramedian sutures; sternites without depressions. Legs 5–20 with one tarsal spur. Prefemur of ultimate legs of males with a digitiform appendix the same length as the prefemur; digitiform appendix with a tuft of hairs located in the median side of the tip.

Redescription (male). Length: 53 mm from the anterior margin of the cephalic plate to the posterior margin of tergite 21. Antennae: left antenna with 23 articles and right with 20 (20 articles in both antennae); two basal articles glabrous (third and fourth basal articles glabrous). Cephalic plate smooth, without sutures and depression, but with median sulcus anteriorly ( Fig. 13 ).

Coxosternal tooth-plates wider than long with 4+4 teeth and with a strong seta on each plate; the two inner teeth closer to each other than to the external ones. Coxosternite with a transverse suture at the base of the toothplates and a very short longitudinal suture (sulcus at the base of dental plates at an obtuse angle at middle, from which a short median line extends caudad). Margin of the forcipular trochanteroprefemoral process with four short denticles, and the tip pointed (not described).

Tergites smooth (all smooth and shining); Tergites 6–20 with complete paramedian sutures (from 5); tergites 2–5 with incomplete very short anterior and posterior sutures; tergites 9–21 with poorly-developed margination, not clearly visible (only 21 marginate); tergite 21 with posterior margin convex, angled (obtusely angular at middle) ( Fig. 14 ).

Sternites 2–20 with short incomplete paramedian sutures; those of the anterior and posterior sternites shorter than in the mid body (generally without distinct furrows); sternites without depressions; sternite 21 shorter than preceding, with posterior margin straight (slightly incurved).

Coxopleuron without spines and with pore-field that covers almost all the coxopleuron, only the posterior end poreless.

Legs 2 with two tarsal spurs (1 to 4); right legs 10, 11, 18, 19 and 20 with one tarsal spur, and 21 without; left legs 8 and 19 with one tarsal spur, and 20 and 21 without (5 to 20). The remaining legs are missing. Prefemur of ultimate legs with a digitiform appendix the same length as the prefemur; the tip of the digitiform appendix has a tuft of hairs located in the median side of the tip (distal end of dorsal or submedian side) ( Fig. 14 ).

Remarks. O. clavifer was described by Chamberlin (1921) as a species of Otostigmus related to O. scabricauda by the digitiform appendix of the prefemur of the ultimate legs. However, it differs from O.

scabricauda by the smooth tergites, absence of keels on tergites, and the absence of a median depression on sternites. Chamberlin (1921) also noticed that the digitiform appendix in the prefemur of the ultimate legs was different from the digitiform appendix of O. scabricauda . In O. clavifer the digitiform appendix is slightly flattened dorsoventrally and the tuft of hair emerges on the median side of the tip. In O. scabricauda the digitiform appendix is also slightly flattened dorsoventrally, but the tuft of hairs emerges at the tip, not on the median side of the tip. Therefore, the type of O. clavifer is more related to O. brunneus than O. scabricauda , the only difference between them being the length of the digitiform appendix of the prefemur of the ultimate legs. As O. clavifer was described in the same work, but one page before O. brunneus , and both are from the same type locality, I consider O. brunneus as a junior synonym of O. clavifer .

Figures

FIGURES 11 – 12. Otostigmus (P.) clavifer. Holotype MCZ IZ no. 2180 (14285), male. 11. Habitus, (dorsal view). 12. Habitus, (ventral view). Scale bars 5 mm.

FIGURES 13 – 14. Otostigmus (P.) clavifer. Holotype MCZ IZ no. 2180 (14285), male. 13. Cephalic plate and tergites 1 – 3. 14. Tergite of ultimate leg-bearing segment and prefemur of ultimate legs showing the digitiform appendix. DA—Digitiform appendix; TH—Tuft of hairs. Scale bars 1 mm.

FIGURES 3 – 4. Otostigmus (P.) brunneus. Holotype MCZ IZ no. 2181 (31416), male. 3. Cephalic plate and tergites 1 – 4. 4. Tergites of antepenult, penultimate and ultimate leg-bearing segments and prefemora of ultimate legs. DA-Digitiform appendix. Scale bars 1 mm.