Scolopendromorph centipedes (Chilopoda: Scolopendromorpha) in the Natural History Museum (London): A review of the hitherto unidentified species collected in Africa, with remarks on taxonomy and distribution, and a new species of Otostigmus (Parotostigmus)
Author
Simaiakis, Stylianos Michail
Natural History Museum of Crete, University of Crete, Knossos Av., Herakleion 71409, Crete, Greece.
ssimaiakis@yahoo.com
Author
Edgecombe, Gregory D.
Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW 7 5 BD, United Kingdom.
text
Zootaxa
2013
2013-11-05
3734
2
169
198
journal article
10.11646/zootaxa.3734.2.5
1175-5326
5275595
36ED88E6-2CEB-4071-8429-A39901B8B9BF
8.
Otostigmus
(
Parotostigmus
)
coltellus
n. sp.
(
Figs 9–14
)
Otostigmus inermis
Karsch, 1884
[non
Porat, 1876
] [partim]
Otostigma productum
Karsch, 1888
[partim]
Diagnosis.
Otostigmus
(
Parostostigmus
)
with four glabrous antennal articles; short, blade-like tooth plate lacking teeth, base of tooth plate set off by transverse suture; paramedian sutures complete from T3 or usually T4; short coxopleural process with two small apical spines.
Type material.
Holotype
(
Figs 9, 10, 12, 13
):
Gulf
of
Guinea
:
Zampalma
,
São Tomé
Isl. [
Democratic Republic of São Tomé and Principe
],
13/9/1949
, leg.
I.L.J. Galbraith
,
BMNH
1950.3.7.127-136 (
Fig. 8
);
paratype
female from same collection
.
Paratype
(
Figs 11, 14
):
Gulf
of
Guinea
:
São Tomé
Isl.,
West Africa
, 1932,
Percy Sladen Memorial
and
Godman Exploration
, leg. W.H.
T
.
Tams
,
1 ex.
,
BMNH 1933.8
.30.239. (
Fig. 8
)
.
Description.
Length to
78 mm
(
holotype
).
Cephalic plate and tergites pale brown to chestnut brown (
Fig. 9
); legs orange-brown.
Antenna extending back to
T5
, with 17 articles in
types
(16 articles in
ZMB 927
), the basal four glabrous (
Fig. 10
). Cephalic plate punctate, variably with a pair of longitudinal depressions posteriorly
.
Coxosternal tooth plates several times wider than long; anterior margin of tooth plate straight, adentate, gently inclined laterally for most of its width, expanding at its lateral corner to from a blunt bulge (
Figs 11, 12
). Single hyaline seta near midline of toothplate, inserting at boundary of strongly pigmented margin. Trochanteroprefemoral process a sclerotized blade, lacking distinct teeth (
Figs 11, 12
).
Second maxillary telopodite with a pretarsal accessory spur; dorsal spine on distal part of article 2.
Tergites smooth, lacking keels or rugosity. Paramedian sutures continuous from
TT
3 or 4–20; mostly with incomplete sutures extending about half length of
T3
.
Margination
complete on
TT
19–21, incomplete from
TT
14– 15.
Sternites
with continuous paramedian sutures to S19, lacking on S20
.
Legs 1 and 2 with two tarsal spurs; legs 3 to 16, 17, 18 or 19 with one tarsal spur, lacking on leg 20; all legs lacking tibial spurs apart from leg 1 (right leg only) in ZMB 927.
Spiracles elliptical, with strongly humped atrial floor.
Tergite of ultimate leg-bearing segment with broadly V-shaped posterior margin, lacking median depression. Sternite of ultimate leg-bearing segment narrowing posteriorly, with nearly straight lateral and posterior margins.
Coxpleural process short, with two small apical spines in
types
(one in ZMB 927) but lacking dorsal or lateral spines. Pore field extends to dorsal and posterior margins of coxopleuron, with only a short, narrow pore-free band at coxopleural process (
Figs 13, 14
).
Ultimate leg relatively slender, relative lengths of podomeres in the ratio prefemur 1, femur 1, tibia 0.88, tarsus 1 0.73, tarsus 2 0.39, pretarsus 0.22; prefemur of even width (in dorsal view) along its length, width distally about one-third its length. Prefemur lacking spines apart from one mid-ventral spine near midlength in ZMB 927. Ultimate leg pretarsus with accessory claws.
FIGURES 9–14.
Otostigmus
(
Parotostigmus
)
coltellus
n. sp.
Holotype BMNH 1950.3.7.127-136 (São Tomé), except figs 11, 14, paratype female from same collection: Figure 9, posterior part of cephalic plate and TT1–4, dorsal view, scale bar 2 mm; Figure 10, left antenna, dorsal view, scale bar 1 mm; Figure 11, forcipular segment, ventral view, scale bar 1 mm; Figure 12, tooth plates, scale bar 0.5 mm; Figure 13, coxopleuron and sternite of ultimate leg-bearing segment, ventral view, scale bar 1 mm; Figure 14, coxopleuron and sternite of ultimate leg-bearing segment, ventral view, scale bar 1 mm.
Etymology.
Coltello
, Italian for knife, with reference to the blade-like tooth plates.
General distribution.
West-Central Tropical Africa: Gulf of
Guinea
(
São Tomé
, Rolas) (ST).
Discussion.
The type material is from the island of
Säo Tomé
; a conspecific specimen (ZMB 927; Museum für Naturkunde, Berlin) from the island of Rolas is a
syntype
of
Otostigmus
(
Parotostigmus
)
productus
Karsch, 1888
but is excluded from that species with the designation of a
lectotype
below.
Compared to all other African
O
. (
Parotostigmus
), this species is readily distinguished by its adentate tooth plates. The most similar species,
O
. (
P
.).
productus
Karsch
, also occurs on
São Tomé
, and the two taxa share some character states that, in combination, separate them from other African
O
. (
Parotostigmus
). These include 17 antennal articles, four of which are glabrous (versus
2–2.5 in
other species), complete paramedian sutures from TT3 or 4, complete paramedian sutures on the sternites, and a pair of coxopleural apical spines. The uniquely adentate tooth plates of
O.
(
P
.)
coltellus
are the same in the four known specimens of the species and this difference from
O
. (
P
.)
productus
cannot be attributed to wear, particularly because the sutures defining the base of the tooth plate are distinct from those of
O
. (
P
.)
productus
. In the latter species, the relatively long tooth plates are set off by oblique sutures (for further details see figures in
O
. (
P
.)
productus
), whereas the suture at the base of the tooth plate in
O
. (
P
.)
coltellus
is approximately transverse (see
Figs 11, 12
). As well, the position of the single hyaline seta on each tooth plate is a reliable marker of the boundary between the sclerotized margin of the tooth plate and its basal plate. The two species are also readily distinguished by the shape of the coxopleural process, being shorter and less slender in
O
. (
P.
)
coltellus
. These two species co-occur in the collection from Zampalma that includes the
holotype
of
O
. (
P
.)
coltellus
. Although a marked size difference separates the two (large) specimens of
O
. (
P
.)
coltellus
from the nine smaller specimens of
O
. (
P
.)
productus
, morphological differences cannot be attributed to changes with growth because the smaller
paratype
of
O
. (
P
.)
coltellus
(BMNH 1933.8.30.239) is scarcely larger than the Zalpalma specimens of
O
. (
P
.)
productus
, yet both species exhibit their typical characters of the tooth plates and coxopleural process.