Description of Alocobisium tibetense sp. nov., representing the first record of the pseudoscorpion family Syarinidae (Arachnida: Pseudoscorpiones) from China
Author
Hu, Junfang
Author
Zhang, Feng
text
Zootaxa
2013
3641
1
49
56
journal article
10.11646/zootaxa.3641.1.5
51f40fc4-5555-4841-986e-251449efab75
1175-5326
283692
6A804C8E-47A4-4381-8363-5C9D7DF908E0
Alocobisium rahmi
Beier, 1976
(
Figs 1–9
)
Alocobisium rahmi
Beier, 1976: 98
–99, fig. 4; Schawaller, 1983: 108–110, figs 8–11; Schawaller, 1987: 209; Harvey, 1991: 418; Schawaller, 1991: 779, fig. 1.
Type
material examined.
Two females (
holotype
and
paratype
, NMB-PSEU00034a), Phuntsholing,
Bhutan
,
600 m
alt.,
15 April 1972
, NMB
Bhutan
Expedition.
Diagnosis.
Carapace smooth and without basal furrow; eyeless; trichobothrium
ib
situated near the base of hand,
st
nearer to
t
than to
sb
.
Description.
Carapace and tergites pale yellow, pedipalps brown (
Fig. 1
).
FIGURE 1.
Alocobisium rahmi
Beier, 1976
, holotype female (right) and paratype female (left), habitus, dorsal view.
Carapace smooth and longer than broad (
Fig. 2
), with a total of 22–23 setae, including 4 on anterior margin and 6–7 on posterior margin; epistome rounded; eyeless; without basal furrow on carapace. Pleural membrane with longitudinal striate and medially weakly granulated.
Tergites I and II each with 8 marginal setae; anterior genital operculum with 4 setae; posterior parts damaged.
Pedipalps (
Fig. 5
) smooth. Apex of coxa with 2 setae. Trochanter without tubercle. Femur with a stout pedicel, proximal half wider than distal half. Patella stout. Fixed chelal finger (
Fig. 7
) with 30 blunt teeth, movable finger with 28 teeth, all teeth contiguous. Trichobothrium
ib
near base of hand, trichobothria
eb
and
esb
on distal portion of hand,
ist
on sub-basal of fixed finger,
eb
,
esb
and
isb
situated in a straight line, 4 antiaxial feather-shaped setae (
Fig. 9
) clustered between
it
and
est
;
st
nearer to
t
than to
sb
, trichobothrium
t
short and acuminate, situated near middle of movable finger.
FIGURES 2–9.
Alocobisium rahmi
Beier, 1976
, holotype (3–9) and paratype (2). 2, carapace, dorsal view; 3, right chelicera, dorsal view (teeth magnified); 4, galea; 5, left pedipalp (without trochanter), dorsal view; 6, left leg IV; 7, right chela, lateral view (with details of teeth); 8, right leg I; 9, feather-shaped setae on right chelal finger, lateral view. Scale lines: 0.4 mm (Figs 2–3, 5–8), 0.05 mm (Figs 4, 9).
Cheliceral palm with 5 setae (
Fig. 3
), movable finger with 1 seta; fixed finger with 8–9 teeth; movable finger with 5–6 teeth; galea (
Fig. 4
) long, simple, without branchlets; rallum and serrulae not examined.
Legs (
Figs 6, 8
); junction between femur and patella of leg IV perpendicular, leg IV basitarsus with one subbasal tactile seta (TS 0.30), telotarsus with one tactile seta (TS 0.22); subterminal seta bifurcate distally, arolium shorter than the thin and smooth claws.
Dimensions (in mm, length/breadth or depth ratios in parentheses).
Body length indeterminable. Carapace 0.34–0.35/0.28 (1.21–1.25). Pedipalps: trochanter 0.16–0.17/0.09 (1.78–1.89), femur 0.30/0.10 (3.00), patella 0.25/ 0.12 (2.08), chela (with pedicel) 0.50–0.51/0.16–0.17 (3.00–3.13), chela (without pedicel) 0.47–0.48 (2.82–2.94), hand length (without pedicel) 0.20 (1.18–1.25), movable finger length 0.26–0.27 (1.30–1.35 times longer than hand without pedicel). Chelicera 0.15/0.10 (1.50), movable finger length 0.13. Leg I: femur 0.13/0.06 (2.17), patella 0.11–0.12/0.05 (2.20–2.40), tibia 0.13/0.04 (3.25), basitarsus 0.07–0.08/0.03 (2.33–2.67), telotarsus 0.10– 0.11/0.02 (5.00–5.50). Leg IV: femur + patella 0.20/0.08 (2.50), tibia 0.20/0.06 (3.33), basitarsus 0.07–0.08/0.04 (1.75–2.00), telotarsus 0.12/0.03 (4.00).
Distribution.
This species is known only from
Bhutan
.
Remarks.
The two
types
of
Alocobisium rahmi
were in the same vial when they were sent to us and the
holotype
was not designated distinctly. Beier (1976) noted that the
paratype
of
A. rahmi
was badly damaged, from which we infer that the specimen shown on the right in
Fig. 1
is the
holotype
. We found that the
holotype
had a damaged abdomen and that the paratype’s abdomen was lost. The right chelae of both
types
were detached, but still present in the vial. Legs were partly fragmentary and the detached parts were lost. The carapace of the
holotype
was cracked anteriorly. Fortunately, the carapace of the
paratype
was in good condition.
The description given by Beier (1976) is generally accurate, except that the number of setae on carapacal posterior margin was found to be
7 in
paratype
and
6 in
holotype
(as opposed to
8 in
Beier’s description), no basal furrow could be seen on the carapace (Beier mentions an indistinct and nearly flat furrow), and the carapace is 1.21–1.25 times as long as broad (almost 1.40 times according to Beier).