The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level
Author
Rix, Michael
Western Australian Museum, Welshpool DC, Perth, Australia
Author
Harvey, Mark
Western Australian Museum, Perth, Welshpool, Australia
text
ZooKeys
2010
2010-02-22
36
36
1
321
journal article
10.3897/zookeys.36.306
4db6b327-7482-432e-a5f6-36f91c79fef3
1313–2970
576620
ADCACC88-6C78-4386-8E33-3F98234ECE92
Genus
Taphiassa
Simon, 1880
Taphiassa
Simon, 1880: 172
.
Type
species by monotypy
Taphiassa impressa
Simon, 1880
.
Roewer, 1942: 414
.
Bonnet, 1959: 4238
. Transferred from
Theridiidae
to
Symphytognathidae
by
Levi & Levi, 1962: 29
. Transferred from
Symphytognathidae
to
Mysmenidae
by
Forster & Platnick, 1977: 2
.
Brignoli, 1980: 730
(also transferred ‘
Taphiassa
’
punctigera
Simon, 1895
to
Theridiidae
incertae sedis
).
Brignoli, 1983: 379
.
Platnick, 2009
.
Parapua
Forster, 1959: 301
.
Type
species by original designation
Parapua punctata
Forster, 1959
.
Brignoli, 1983: 374
.
Platnick, 2009
.
syn. n.
(but see also
Brignoli, 1980: 731
).
Affinities
.
The genus
Taphiassa
appears to be the sister-lineage to
Olgania
from
Tasmania
(
Fig. 4
).
Diagnosis
.
Species of
Taphiassa
can be distinguished from species of
Olgania
by the presence of a normal, plate-like anterior sclerite (Fig. 165C), the presence of an enlarged subtegulum (Fig. 174A), and the presence of a seta projecting from the proximal toothed mound of the cheliceral promargin (Figs 159B, 172F). Other diagnostic characters include the presence of eight eyes (Fig. 152A), and the absence of bulging anterior projections on the male chelicerae (Fig. 157E).
Description
.
Very small, entelegyne
Araneoidea
: total length 1.00 to 2.20.
Cephalothorax
: Carapace with glandular depressions above maxillae (Figs 170E, 170G– H); cuticle of carapace and sternum heavily punctate, covered with glandular pits (Figs 152A–C); margins fused to sternum via pleural sclerites. Eight eyes present on anterior margin of pars cephalica (Fig. 152A); eyes usually subequal, AME greater than three-quarters diameter of ALE (Fig. 152C). Chelicerae without bulging anterior projections in males; promargin with one sessile tooth and separate proximal, toothed mound near tip of fang bearing prolateral seta (Figs 159A–B); fused setal sockets, peg teeth and ectal stridulatory ridges absent.
Legs and female pedipalp
: Legs three-clawed (Figs 160E–F), covered with smooth or serrate hair-like setae; superior claws of legs I–II often strongly pectinate (Figs 173D– E); superior claws of legs III–IV usually asymmetric (Fig. 173F). Trichobothria present on legs; tibiae each with three (legs I–III) or four (legs III–IV) trichobothria; metatarsi each with (legs I–IV) (Fig. 160C) or sometimes without (leg IV) single trichobothrium. Female pedipalp entire (Fig. 159C), reduced or vestigial (Fig. 170F); claw absent (Fig. 159D).
Abdomen
: Abdomen globose; anterior sclerite present around epigastric region and petiole; dorsal scute absent on males and females (Figs 155A–B); posterior sclerotic ring surrounding spinnerets and colulus. Six spinnerets situated posterior to fleshy colulus (Figs 162, 175); PMS with single medial AC gland spigot and posterior seta; PLS with reduced triad consisting of FL gland spigot and single AG gland spigot. Anterior tracheal system well-developed, with multiple radiating tracheae (Figs 169E–F); posterior tracheal spiracle vestigial (Figs 152F, 154D).
Genitalia
: Male pedipalp (Figs 161, 174) relatively small; patella with retrolaterallydirected, hooked ligulate retrolateral apophysis and strongly recurved distal apophysis; subtegulum enlarged, bulging posteriorly; tegulum smooth, with curved evaginated tegular ridge; embolus exposed, long (length> 5× width), curving distally. Female genitalia (Figs 154A–C, 169) with pair of separate, globular anterior spermathecae; insemination ducts simple, straight; fertilisation ducts simple, curved.
Distribution
.
Eastern and south-western mainland
Australia
,
Tasmania
, Lord Howe Island,
New Caledonia
and
New Zealand
(Fig. 217).
Composition
.
Two described species,
Taphiassa impressa
Simon, 1880
and
T. punctata
(
Forster, 1959
)
and the four new species
T. castanea
,
T. globosa
,
T. magna
and
T. robertsi
. Undescribed species are also known from
New Caledonia
and eastern
Australia
. Note that the species
Taphiassa punctigera
Simon, 1895
is a
Theridiidae
incertae sedis
(
Brignoli 1980
;
Platnick 2009
), not conspecific or congeneric with
T. impressa
.
Nomenclatural
remarks.
The genus
Taphiassa
was originally described by
Simon (1880)
for the species
T. impressa
, from Nouméa,
New Caledonia
. No illustrations were provided with the original description, and the species had never been adequately illustrated (
Brignoli 1980
).
Levi and Levi (1962)
transferred
T. impressa
from the
Theridiidae
to the
Symphytognathidae
, while
Forster and Platnick (1977)
transferred it from the
Symphytognathidae
to the
Mysmenidae
. It was
Brignoli (1980)
who, with remarkable insight aided only be Simon’s original Latin description, first noted the similarity of
T. impressa
to
Parapua
, and the analysis of
Rix et al. (2008)
also inferred a close sister-group relationship between
Taphiassa
and
Parapua
.
Taphiassa
is hereby transferred from the
Mysmenidae
to the
Micropholcommatidae
, and
Taphiassa
is formally recognised as a senior generic synonym of
Parapua
.
Taxonomic
remarks.
Species of
Taphiassa
can be arbitrarily divided into two groups based upon somatic features – the ‘
Taphiassa
group’ and the ‘
Parapua
group’. Species in the ‘
Parapua
group’ (including
T. punctata
,
T. castanea
and similar species) are generally smaller, darker coloured, with relatively shorter legs and smaller female pedipalps than species in the ‘
Taphiassa
group’, which are often relatively large with strongly patterned abdomens. A spectrum of intermediate morphologies exists, however, and the division seems merely phenetic. Many additional species of
Taphiassa
are known from
Australia
and
New Caledonia
(e.g. see
Platnick 1993
under “
Parapua
”), and the genus has clearly radiated in
New Caledonia
, with at least five undescribed species represented in museum collections (M. Rix, unpubl. data).