The millipede genus Lissodesmus Chamberlin, 1920 (Diplopoda: Polydesmida: Dalodesmidae) from Tasmania and Victoria, with descriptions of a new genus and 24 new species
Author
Mesibov, Robert
text
Memoirs of Museum Victoria
2005
2005-12-31
62
2
103
146
https://museumsvictoria.com.au/collections-research/journals/memoirs-of-museum-victoria/volume-62-issue-2-2005/pages-103-146/
journal article
10.24199/j.mmv.2005.62.4
1447-2554
8064747
Lissodesmus cognatus
sp. nov.
Figures 25
,
26
,
27
,
69
cog, 70cog, 71cog, 76 (map)
Lissodesmus
sp.
NE3.—
Mesibov, 1996: 17
.—
Mesibov, 1997:
567.—
Mesibov, 2003a: 209
.
Material examined.
Holotype
.
Male
,
Australia
,
Tasmania
.
Weavers Creek
, EQ
330091 (
41°28'07''S
147°23'42''E
),
380 m
,
31.vii.1994
,
R. Mesibov
&
T. Moule
,
QVM 23
:15287.
Paratypes
.
2 males
,
North Esk River
, EQ336079 (
41°28'46''S
147°24'08''E
),
490 m
,
23.ii.1992
,
R. Mesibov
,
QVM 23
:15284;
2 males
, “
Elkington
” property, EP312979 (
41°34'11''S
147°22'27''E
),
350 m
,
18.iii.1992
,
R. Mesibov
,
AM
KS91171
(ex
QVM 23
:15283)
;
4 males
, same details,
QVM 23
:15283, 2 dissected
;
2 females
,
Weavers Creek
, EQ307122 (
41°26'27''S
147°22'02''E
),
680 m
,
19.vii.1994
,
R. Mesibov
,
QVM 23
:
15289; male,
Tower Hill, EP
708983 (
41°33'49''S
147°50'56''E
),
720 m
,
31.xii.1998
,
R. Mesibov
& K.
Bonham
,
QVM 23
:40758
;
10 males
,
Coxs Creek
, EQ767040 (
41°30'42''S
147°55'08''E
),
480 m
,
ii.2001
,
R. Bashford
,
pitfall
sample,
QVM 23
:24738, 2 dissected
.
Other material.
14 males
,
2 females
and
5 juveniles
from “Aplico” property,
Coxs Creek
,
Grants Creek
,
Long Gully Creek
,
Musselboro
,
Rabbity Creek
,
Tower Hill
and
Weavers Creek
(see “
Lissodesmus
supplement” for details)
.
Description
. Male c.
14 mm
long,
H
= 1.3 mm. In alcohol, well-coloured specimens under low magnification near-white in body colour with red tinge transversely near posterior margins of metatergites and dorsa of prozonites. Antennae long, slender (
Fig. 69
cog), about 2.5X a socket diameter apart.
Paranota
reduced,
R
= 1.3 (
Fig. 70
cog); posterior corners turned up slightly. Legs fairly slender, tarsus about as long as femur, tibia with slight ventral distal swelling (
Fig. 71
cog). Telopodite (
Figs 25
,
26
,
27
) reaching leg 5 when retracted. Solenomere arising at half the telopodite height, directed posterodistally at a small angle to telopodite axis, terminating with toothed subapical collar at about half the prefemoral process height. Tibiotarsus a slightly flattened, bluntly pointed rod about as wide as solenomere but shorter, more or less parallel to solenomere but gradually curving laterally.
Femoral process arising proximal to solenomere origin (at about one-third the telopodite length), pressed close to prefemoral process proximally, forked near base; branches more or less equal, blade-like, pointed, the anterior branch directed distally and terminating at level of solenomere tip, the posterior branch curving anteriorly, its tip sometimes lying between anterior branch and prefemoral process. Prefemoral process about half the width of telopodite base, bending posteriorly at about two-thirds its length and tapering, the flexed distal section bearing a comb of c. 15-20 large, irregular, proximally directed teeth.
Uncus prominent, arising at about half the prefemoral process length (about the level of the solenomere tip) on well-defined longitudinal ridge near lateral edge of process.
Distribution and habitat.
An uncommon species known from wet eucalypt forest in two disjunct areas c.
35 km
apart in north-east
Tasmania
(
Fig. 76
): south and west of Mt Barrow (c.
30 km
2
), and north and east of Tower Hill (c.
15 km
2
).
Etymology
. Latin
cognatus
(“kindred”), adjective. At first glance,
L. cognatus
seems to be closely related to both
L. alisonae
and
L. hamatus
.
Remarks
. Furry individuals of
L. cognatus
have been found near the North Esk River, Weavers Creek and Musselboro. Specimens from the “Elkington” property, a few kilometres to the south in the South Esk River catchment, are non-furry, as are all specimens from the Tower Hill portion of the range. I have previously speculated (
Mesibov, 1997
,
2003a
) that
L. cognatus
is a stabilised hybrid of
L. alisonae
and
L. hamatus
, i.e. a product of reticulate evolution. The two putative parents meet with minimal overlap in the western block of the
L. cognatus
range, and
L. hamatus
occurs in the eastern block.