Austrarchaea Forster & Platnick, 1984

Rix, Michael G. & Harvey, Mark S., 2012, Australian Assassins, Part III: A review of the Assassin Spiders (Araneae, Archaeidae) of tropical north-eastern Queensland, ZooKeys 218, pp. 1-50 : 3-4

Genus Austrarchaea Forster & Platnick, 1984

Austrarchaea Forster & Platnick, 1984: 21; Rix and Harvey 2011: 14.

Type species.

Archaea nodosa Forster, 1956, by original designation.

Diagnosis. Species of Austrarchaea can be distinguished from all southern Australian species of Zephyrarchaea by the significantly taller carapace (CH/CL ratio ≥ 2.0), by the presence of accessory setae on the distal bulge of the male cheliceral paturon, and by the fusion of the two conductor sclerites on the male pedipalp ( Rix and Harvey 2012a, fig. 4). Australian Archaeidae are further distinguished from Old World taxa by the presence of numerous, clustered spermathecae in females (Fig. 7G), and by the presence of a long, wiry embolus on the pedipalp of males (Fig. 4).

Description.

For a full generic description see Rix and Harvey (2011). For notes on genitalia and morphological differences among lineages of Austrarchaea , see Remarks (below).

Distribution.

Species of Austrarchaea occur in mesic habitats throughout eastern Queensland and New South Wales (Fig. 3), usually in montane rainforests (Figs 1E-F), but also in lowland rainforests or wet eucalypt forests on or adjacent to the Great Dividing Range ( Rix and Harvey 2011). In north-eastern Queensland, archaeids occur throughout the Wet Tropics bioregion, from the Mount Finnigan Uplands (near Cooktown) south to Mount Elliot (near Townsville) (Figs 16-23, 25). In the Mackay and Whitsundays Hinterland region, archaeids can be found in the Eungella National Park (near Mackay), north to Mount Dryander (south of Bowen) (Figs 24-25). The genus is not known to occur south or west of the Australian Alps (Fig. 2), which may be a vicariant biogeographic barrier between populations of Austrarchaea and Zephyrarchaea ( Rix and Harvey 2012a, 2012b).

Composition.

Nineteen described species - Austrarchaea alani Rix & Harvey, 2011, Austrarchaea aleenae Rix & Harvey, 2011, Austrarchaea binfordae Rix & Harvey, 2011, Austrarchaea christopheri Rix & Harvey, 2011, Austrarchaea clyneae Rix & Harvey, 2011, Austrarchaea cunninghami Rix & Harvey, 2011, Austrarchaea daviesae Forster & Platnick, 1984, Austrarchaea dianneae Rix & Harvey, 2011, Austrarchaea harmsi Rix & Harvey, 2011, Austrarchaea helenae Rix & Harvey, 2011, Austrarchaea judyae Rix & Harvey, 2011, Austrarchaea mascordi Rix & Harvey, 2011, Austrarchaea mcguiganae Rix & Harvey, 2011, Austrarchaea milledgei Rix & Harvey, 2011, Austrarchaea monteithi Rix & Harvey, 2011, Austrarchaea nodosa (Forster, 1956), Austrarchaea platnickorum Rix & Harvey, 2011, Austrarchaea raveni Rix & Harvey, 2011, Austrarchaea smithae Rix & Harvey, 2011 - plus the eight new species from north-eastern Queensland: Austrarchaea griswoldi sp. n., Austrarchaea hoskini sp. n., Austrarchaea karenae sp. n., Austrarchaea tealei sp. n., Austrarchaea thompsoni sp. n., Austrarchaea wallacei sp. n., Austrarchaea westi sp. n. and Austrarchaea woodae sp. n.

Remarks.

The genus Austrarchaea includes three major lineages in eastern Australia (Figs 3-4), each readily distinguished by the morphology of the abdomen and the structure of the male pedipalp (Fig. 4). The most widespread lineage (the Austrarchaea nodosa species-group) occurs south of the St Lawrence Gap, from Kroombit Tops National Park in central Queensland, south to the Badja State Forest in southern New South Wales (Fig. 3); species in this lineage possess six dorsal hump-like tubercles on the abdomen and an exposed tegular cavity with a variably scutiform conductor (Fig. 4). The second, most restricted lineage (the Austrarchaea monteithi lineage) is known only from the Gibraltar Range National Park in northern New South Wales (Fig. 3); the single known species, Austrarchaea monteithi , possesses five dorsal hump-like tubercles on the abdomen and an exposed tegular cavity with a hooked conductor (Fig. 4). The third lineage (the Austrarchaea daviesae species-group; revised in this paper) occurs north of the St Lawrence Gap, from Eungella National Park north to Cooktown (Figs 3, 25); species in this lineage possess only four dorsal hump-like tubercles on the abdomen (recumbent in Austrarchaea woodae sp. n.) and a more enclosed tegular cavity with a very large, arched conductor (Figs 4, 6-15).

Although the derived pedipalpal morphology of Austrarchaea daviesae and its relatives is strikingly different to that of congeners further south, the distal tegular sclerites can nonetheless be broadly homologised with those of Austrarchaea nodosa and Austrarchaea monteithi on the basis of their shape and relative position in the unexpanded tegular cavity. The embolus in all nine known north-eastern Queensland species is a long, sinuous, strongly sclerotized process emerging from the distal bulb pro-ventrally, in some species bearing an additional accessory spur. Tegular sclerite 3 (TS 3) is always a prominent, pro-ventrally directed process, which is fused to the retro-ventral margin of the tegular bulb (the latter of which is usually also concomitantly modified). Tegular sclerite 2 (plus 2a, i.e. TS 2-2a) is usually inserted just behind TS 3 in the unexpanded tegular cavity, forming a distinctive, mesally-looped and distally whip-like structure common to all taxa in the Austrarchaea daviesae species-group; the extent of this very long, whip-like TS 2a is usually proximate to the distal extension of the embolus in the unexpanded state. This TS 2-2a morphology is in stark contrast to that of Austrarchaea monteithi , Austrarchaea nodosa and related species, in which TS 2a is usually covered and largely obscured by a more spur-like TS 2 process. Tegular sclerite 1 (TS 1) - generally the most prominent sclerite in species of Zephyrarchaea and other species of Austrarchaea - is reduced and often obscured in most archaeid species from north-eastern Queensland, although a few taxa possess a larger, more distinctive TS 1 posterior to the TS 2-2a complex (e.g. Fig. 9D). Inter-specific variation among taxa in the Austrarchaea daviesae species-group is pronounced, with male pedipalp morphologies usually highly autapomorphic for each species. Five broad pedipalp types (Types A-E) can be distinguished among north-eastern Queensland taxa, with Type A being the most common form, shared between five of the nine known species, and Types B-E each currently unique to single species. Figure 6 highlights differences between these different pedipalp morphologies, which are further diagnosed in the Key to species (see below).

Key to the species of Austrarchaea known from north-eastern Queensland (males required)