Ampliphallus, Cruz-López & Francke, 2020

Cruz-López, Jesús A. & Francke, Oscar F., 2020, Two new genera of epigean harvestmen (Opiliones, Stygnopsidae) from Oaxaca, Mexico, with an identification key for the stygnopsine genera, Zootaxa 4748 (3), pp. 431-454 : 433-434

Ampliphallus gen. nov.

urn:lsid:zoobank.org:act:14CE9488-3AA7-40C2-AF36-2CEAEB51E772

Type species. Ampliphallus chimalapaensis sp. nov., designated in the present work.

Etymology. From the Latin amplus, wide and phallus, penis, in reference to the pars distalis, noticeably wider than in all other stygnopsine harvestmen. Grammatical gender is masculine.

Diagnosis. Ampliphallus gen. nov. can be recognized from the non-troglobitic stygnopsine genera in which the mid-bulge of the scutum lacks lateral clear areas ( Guelaguetzia gen. nov., Hoplobunus and Isaeus ) by the following combination of characters: (a) ocularium apically rounded without spine ( Fig. 3 )—spine present and small in Hoplobunus , large in Isaeus and absent in Guelaguetzia gen. nov.; (b) mesotergal area III without paramedian spines ( Figs. 1–4 )—a small pair in Isaeus , absent in Hoplobunus and Guelaguetzia gen. nov. too; (c) anal plate with long and cylindrical setiferous tubercles in both sexes ( Figs. 1, 2 and 6 ); (d) pedipalpal patella without dorso-apical apophysis, covered by small spiniform tubercles ( Fig. 9 )—apophysis present in both Hoplobunus and Isaeus and absent in Guelaguetzia gen. nov.; (e) both ventral rows of tubercles on femur IV formed by tubercles similar in size, small and tooth-shaped ( Figs. 13–15 )—small and spiniform in Isaeus , cylindrical, contiguous and increasing in size distally in Hoplobunus and in Guelaguetzia gen. nov. the retrolateral row with very long tubercles; and (f) by the male genitalia, with the pars distalis as wide as long, soft and dorsally bent, with a basal articulation in truncus-pars distalis, with two pairs of macrosetae B on the truncus, just below of pars distalis ( Figs. 16–18 ). Also, the shape of pars distalis of penis and the macrosetal arrangement are very distinct from other known stygnopsine genera.

Geographical distribution. This genus is only known from the type locality and paratypes records of A. chimalapaensis sp. nov. ( Fig. 57 ).

Natural history. The specimens of A. chimalapaensis sp. nov. were found under the bark of decomposed trees. Those specimens collected in the cave were found under rocks near the cave entrance.

Figures

FIGURE 57. Distribution map of Ampliphallus chimalapaensis gen. nov., sp. nov. (white circle) and two species of Guelaguetzia gen.nov.: G. cuicateca sp. nov. (black square) and G. serrana sp. nov. (white square).

FIGURES 1–3. Ampliphallus chimalapaensis sp. nov., holotype male (CNAN-T01327) and paratype female (CNAN-T T01328). 1, habitus holotype, dorsal view. 2, habitus female, dorsal view. 3, lateral view holotype. Scale bars: 1 mm.

FIGURES 4–6. Ampliphallus chimalapaensis sp. nov., holotype male (CNAN-T01327). 4, dorsal scutum. 5, venter. 6, anal plate, ventral view. Scale bars: 1 mm.

FIGURES 7–10. Ampliphallus chimalapaensis sp. nov., holotype male (CNAN-T01327). 7, chelicera, frontal view. 8, chelicera, mesal view. 9, pedipalp, mesal view. 10, pedipalpal tibia and tarsus, ventral view (major spiniform setiferous tubercles on tibia indicated as T1–T3). Scale bars: 1 mm.

FIGURES 11–15. Ampliphallus chimalapaensis sp. nov., holotype male (CNAN-T01327). 11, trochanter IV, dorsal view. 12, trochanter IV, ventral view. 13, leg IV, ectal view. 14, leg IV, mesal view. 15, femur IV, ventral view. Scale bars: 1 mm.

FIGURES 16–18. Ampliphallus chimalapaensis sp. nov., penis of holotype male (CNAN-T01327). 16, dorsal. 17, lateral. 18, ventral. Macrosetae groups: yellow=A, blue=B, pink=C, green=D. Scale bars: 100 µm.