Dactylochelifer martensi, Dashdamirov, Selvin, 2006

Dashdamirov, Selvin, 2006, A new species of the false­scorpion family Cheliferidae from Thailand, with remarks on Ancistrochelifer and Metachelifer (Arachnida: Pseudoscorpiones), Zootaxa 1325, pp. 347-362 : 353-357

? Dactylochelifer martensi sp. n.

Figs 15–28

Type material. Male holotype: SMNS 3053, Thailand, Prov. Chiang Mai, N Doi Suthep [5], 18°48´N, 98°55´E, 1400 m, under bark, 31 December 1988, leg. J. Trautner & K. Geigenmüller; Female paratype: same data as for holotype.

Etymology. Honours Prof. Dr Jochen Martens (University of Mainz, Germany), an outstanding specialist in several arthropod and vertebrate groups, on the occasion of his 65th anniversary.

Diagnosis. Differs from other known congeners by the subterminal seta, which is simple; cheliceral setae B and SB are devoid of denticulation terminally; the lateral rods are not fused anteriorly but with a poorly­visible, membranous bridge; the apodeme of the reversible sacs and the lateral apodeme in the male genitalia are peculiar in shape, same as the aperture of the coxal sacs, which open towards the mesal, proximal corner.

Description. Slender dactylocheliferine of typical facies. Colour of carapace, palps and tergites reddish brown, remaining parts (legs, sternites and pleural membranes) light yellowish brown. Carapace with a pair of well­developed eyes, slightly (1.04 times) longer than broad, surface evenly and strongly granular; both transverse furrows prominent, regularly granular. Dorsal setae of carapace, palps and tergites short and denticuloclavate. Chaetotaxy of carapace: anterior margin with four, posterior margin with 13 deniculoclavate setae borne on larger but relatively inconspicuous tubercles; a total of 70 setae. Tergal chaetotaxy: 15:14:17:16:22:21:20:20:21:17:14(12+2 long tactile setae):2 (short, simple setae). Coxa IV with an anterolateral process and ca 42 setae. Coxal sac taking up only 1/3 coxal length. Atrium absent, aperture of coxal sac opening immediately at, not just near, mesal, proximal corner. Sternal chaetotaxy: x:50:24 (4+8+12):12:13:12: 12:13:14 (12+2 long pseudotactile (?) setae):12(10+2 long tactile setae):2 short and acuminate setae.

Structure of male genitalia of dactylocheliferine form, as illustrated ( Figs 24, 25 ): lateral rods complex, especially in basal part, not fused anteriorly but with a poorlyvisible, membranous bridge; dorsal apodeme large as compared to that of other congeners. Reversible sacs large; apodeme of reversible sac and lateral apodeme well­developed.

Basal part of chelicera and entire movable finger with scale­like sculpture dorsally; five setae in basal part, setae SB and B simple, not denticulate; movable finger with a seta distad of midway of finger; serrula exterior with 18 lamellae; lamina exterior present; flagellum with three blades, anterior two weakly denticulate distally (first blade with nine spinules, second with only one spinule). Galea with five short terminal branches. Fixed finger with three small and flat intermediate teeth.

Palp with trichobothriotaxy as illustrated ( Figs 16, 22 ). Palp slender, all segments with well­developed granulation, except for chelal fingers, which are smooth; dorsal setae short and prominently denticulate; proportions: trochanter 1.79 times as long as broad; femur 5.59 times as long as broad; patella 4.12 times as long as broad; chela with pedicel 5.03 times as long as broad, its chaetotaxy pattern, venom apparatus and dentition as illustrated ( Fig. 16 ); chela without pedicel 4.83 times as long as broad. Hand with pedicel 2.46 times, without pedicel 2.14 times, as long as broad. Movable finger 1.08 times as long as hand with pedicel, and 1.24 times without pedicel. Fixed finger of chela with 52 marginal teeth (two small, weakly developed situated near venom tooth) and with six pores (sensory spots) situated on lateral side, linearly between ESB and EST; movable finger with 52 marginal teeth and five pores (sensory spots) situated on lateral side. Lamina defensor of fixed finger with a subapical notch on anterior side.

Venom apparatus present in both chelal fingers, venom duct in both fingers level to trichobothrium T.

Leg IV of typical facies, tibia and tarsus without tactile setae, with numerous denticulate setae, well­visible scale­like sculpture and simple claws; proportions: femur+patella 3.5 times as long as deep; tibia 5.8 times as long as deep; tarsus 5.64 times as long as deep, with simple claws ( Fig. 28 ). Subterminal tarsal seta simple, arolium shorter than claws, small protuberances on ventral side of claws ( Fig. 28 ).

Leg I: surface weakly scale­like sculptured; tibia 4.06 times as long as deep; tarsus 4.34 times as long as deep. Subterminal tarsal seta simple. Claws modified and asymmetrical ( Figs 26 & 27 ): lateral claw with a large mediodorsal tooth.

Measurements (length/breadth, in mm).

Carapace 0.93/0.89. Palp: trochanter 0.50/0.28; femur 1.23/0.22; patella 1.03/0.25; chela with pedicel 1.76/0.35; length of chela without pedicel 1.69; length of hand with pedicel 0.86, without pedicel 0.75; length of movable finger 0.93. Leg IV: femur+patella 0.84/0.24; tibia 0.70/0.12; tarsus 0.502/0.09. Leg I: tibia 0.45/0.11; tarsus 0.43/0.10.

Brief description of paratype. Carapace slightly (1.02 times) longer than broad. Chaetotaxy: anterior margin with four setae, posterior margin with ten setae (total ca 77 setae). Tergal chaetotaxy: 14:15:15:20:19:20:20:20:18:16:17(15+2 long pseudotactile (?) setae):2(short, but incrassate and denticulate terminally). Sternal chaetotaxy: 17:11:9:13:13:12:12:13:13:13(11+2 long tactile setae):2 short and acuminate setae; only one central cribriform plate present ( Fig. 18 ).

Proportions of pedipalp: trochanter 1.93 times as long as broad; femur 5.39 times as long as broad; patella 4.04 times as long as broad; chela with pedicel 4.62 times as long as broad, without pedicel 4.14 times as long as broad. Hand with pedicel 2.30 times, without pedicel 2.03 times, as long as broad. Movable finger 1.07 times as long as hand with pedicel, and 1.21 times without pedicel. Both chelal fingers with 52 marginal teeth.

23).

Measurements (length/breadth, in mm).

Carapace 0.97/0.95. Palp: trochanter 0.50/0.26; femur 1.24/0.23; patella 1.05/0.26; chela with pedicel 1.83/0.40; length of chela without pedicel 1.64; length of hand with pedicel 0.91, without pedicel 0.80; length of movable finger 0.97.

Remarks. It is quite difficult to provide a clear­cut diagnosis of another of the numerous species which can be assigned to such a large and taxonomically confused genus as Dactylochelifer . Instead, its position is rather intermediate between Dactylochelifer and Hysterochelifer , the latter likewise a large and difficult genus.

The absence of an atrium in coxa IV and the trichobothiotaxy are the same as in Hysterochelifer . Some further characters, however, do not fit. Thus, the simple subterminal seta, the cheliceral setae B and SB devoid of denticulation terminally, the single cribriform plate and the lateral rods not fused anteriorly are all rather characteristic of Dactylochelifer . On balance,? D. martensi seems better to be assigned, at least for the time being, to Dactylochelifer . Very probably, in future the artificial “Hysterochelifer­ Dactylochelifer ” complex is to be split into several natural groups. In this case,? D. martensi may well prove to represent a new, yet undescribed genus.

Figures

FIGURES 15 – 28.? Dactylochelifer martensi sp. n., male holotype (15, 17, 19 – 22, 24 – 28) and female paratype (16, 18, 23): 15 coxae IV, ventral view; 16 lateral view of right chelal fingers; 17 tip of fixed chelal finger, lateral view, showing lamina defensor; 18 cribriform plate; 19 chelicera, dorsal view; 20 galea; dorsal view; 21 last tergites (note the absence of granulation); 22 left palp, dorsal view; 23 flagellum; 24 genitalia, dorsal view; 25 lateral view of lateral rod; 26 tarsus and tibia of leg I, lateral view; 27 tarsal claws of leg I, lateral view; 28 tarsal claws of leg IV, lateral view. Scale: 0.6 (16, 22), 0.5 (21, 26), 0.2 (15, 19, 24 – 25), 0.1 (17, 20, 27 – 28), and 0.05 mm (18,