Homolophus gobiensis Tsurusaki, Tchemeris & Logunov, 2000

Snegovaya, Nataly Yu. & Cokendolpher, James C., 2021, Further studies on harvestman genus Homolophus (Opiliones: Phalangiidae), with descriptions of two new species, Zootaxa 4908 (3), pp. 301-353 : 331-333

Homolophus gobiensis Tsurusaki, Tchemeris & Logunov, 2000

Figures 4 , 21–22

Homolophus gobiensis Tsurusaki, Tchemeris & Logunov, 2000: 80–83 , figs. 6–8; Staręga 2003: 96; Mikhailov 2016: 331–332

Diagnosis. The species differs from all species, including the most closely related, Homolophus charitonovi ( Gricenko, 1972) , by the following: chelicerae and pedipalps are short and enlarged. Penis conspicuously dorsoventrally flattened and with extremely widen truncus. Legs are short (ratio of length of first leg femur to body length = ca. 0.4 in both sexes).

Type Locality. Mongolia, South Gobi Aimak , 15 km west of Tsogt-Tsetsy, ca. 43”38’N, 104’35’E .

Distribution. Mongolia and here newly recorded from China ( Fig. 4 ).

Specimens Examined. CHINA, Inner Mongolia Province, Alashan desert, end of October 1901 (1 male, 3 females, ZIN) ; same locality, 1– 2.10.1900 (2 males, ZIN) ; Key Xiao-Shaob-Shui, about 1524 m a.s.l., the southern outskirts of Gobi (1 male, 1 female, ZIN) ; Lake Rhombo Mzo , 3962 m a.s.l., August 1900 (1 female, ZIN) ; Kozlov Mongolian-Tibetan expedition, Hurkhu mountains , 1– 7.11.1925, field # N 469-926, leg. Przhevalsky, 2 females, ZIN ). MONGOLIA, Mongolian Altai, Kobdo lakes, 548 m a.s.l. (2 females, ZIN) ; Ulan Bator (formerly Urga), Khursu Mt. , 31.07– 27.08.1925, field collection N469-926, leg. Przhevalsky (2 males, 1 female, ZIN) ; lower course of Baidarik River , 30.08.1926, leg. A. Kirichenko (2 males, 1 female, ZIN) .

Description. Very large harvestmen, male body rectangular, with rounded corners; heavily sclerotize d body cuticle, slender, 1.78 times longer than wide; length 10.0 mm, width 5.6 mm; body darker in front, behind light brown with distinct saddle, with longitudinal, light-colored, indistinct dashed stripe running length of abdomen. Dark areas just above muscle attachment sites (compare to Fig. 1A ). Thorax with transverse rows of large denticles. Ocularium low, round, small, 1.9 times its length from anterior margin of cephalothorax, with 5 small denticles on each side. Preocular area with group of small denticles, on sides around ocularium with 2–3 small denticles. Legs short, angular in cross-section, I and III pairs (especially Fe) significantly thickened (sexually dimorphic); with longitudinal rows of denticles; Leg lengths (mm): I 3.6 + 1.8 + 3.4 + 4.0 + 5.6 = 18.4, II 5.6 + 2.0 + 5.0 + 5.0 + 6.0 = 23.6, III 3.5 + 1.6 + 3.2 + 4.5 + 4.2 = 17.0, IV 5.0 + 2.0 + 4.4 + 6.2 + 8.0 = 25.6. Pedipalp enlarged (sexually dimorphic), Fe dorsally and ventrally with large and high denticles, laterally with small denticles; Ti dorsally with few smaller denticles, ventrally with denticles, dorsally and ventrally with small denticles; Ta ventrally with row (2–3 denticles wide) of small sensory denticles. Pedipalp segment lengths (mm): 2.2 + 1.2 + 1.4 + 2.0 = 6.8. Chelicerae enlarged (sexually dimorphic) with some tabby marks, basal segment dorsally with group of denticles, distal segment dorsally with several denticles. Cheliceral basal segment length 3.5 mm ventrally with with slightly pointed rounded bulge, distal segment length 4.2 mm. Penis wide (widest at about first 1/3 length), truncus dorsoventrally flattened, bowed, recurved in lateral view, long, slightly tapering to glans, with short ridge or alae on truncus apically (just basal to junction of glans), length (mm): truncus 3.8, glans 0.5, stylus 0.1.

Female differs from male in larger size and more rounded body shape, presence of microdenticles over all surfaces of cephalothorax, presence of large number of small denticles in front of ocularium, less developed legs (shorter and less thickened). Body oval; less slender, 2 times longer than wide. Chelicerae and pedipalp small, armaments weakly expressed. Female body length 10.0 mm, width 5.0 mm. Leg lengths (mm): I 2.5 + 1.6 + 2.5 + 1.9 + 4.8 = 13.3, II 4.8 + 1.8 + 4.2 + 3.5 + 9.0 = 23.3, III 2.5 + 1.2 + 2.5 + 3.4 + 4.8 = 14.4, IV 4.0 + 1.5 + 3.5 + 5.2 + 7.5 = 21.7. Pedipalp segment lengths (mm): 1.3 + 0.7 + 0.8 + 1.4 (4.2). Cheliceral basal segment length 1.6 mm, distal segment length 2.1 mm.

Comments. Specimens over 100 years old. Colors likely faded.

Figures

FIGURE 1. Homolophus anatomy, males: A, kozlovi sp. nov., body, dorsal showing muscle attachment sites in black (color photograph Fig. 23); B, gobiensis outline of body showing denticles (compare Fig. 21A); C, betpakdalensis denticles (compare Fig. 12A); D, pallens denticles (compare Fig 30C); E, chemerisi leg I metatarsus with characteristic thickly packed “brushes” of short setae at higher magnification (see insert); F, albofasciatus denticles (compare Fig. 3A); G, nordenskioeldi (from Murmansk) penis, dorsal; muscle presence more evident in magnified sections. Scale lines: A–D, F = 1 mm; E = 0.5 mm, insert greatly magnified, G = 0.25 mm.

FIGURE 4. Distribution of some Homolophus species in the Palearctic: Central and Inner Asia. Data for pale colored symbols taken from literature; identifications not verified.

FIGURE 21. Homolophus gobiensis Tsurusaki, Tchemeris & Logunov, 2000: A, male body, dorsal; B, male ocularium, dor- sal; C, female body, dorsal; D, female ocularium, dorsal; E, male right chelicera, ectal; F, male right chelicera, mesal; G, male right pedipalp, mesal; H, male right pedipalp, ectal; I, female right chelicera, mesal; J, female right chelicera, ectal; K, female right pedipalp, ectal; L, female right pedipalp, mesal.

FIGURE 22. Homolophus gobiensis Tsurusaki, Tchemeris & Logunov, 2000, male: A, femur I, dorsal; B, penis, dorsal; C, penis glans, dorsal; D, penis, lateral; E, penis glans, lateral.