Neopantopsalis, Taylor, Christopher K. & Hunt, Glenn S., 2009

Taylor, Christopher K. & Hunt, Glenn S., 2009, New genus of Megalopsalidinae (Arachnida: Opiliones: Monoscutidae) from north-eastern Australia, Zootaxa 2130, pp. 41-59 : 45-46

Neopantopsalis n. gen.

Type species. Neopantopsalis quasimodo n. sp.

Diagnosis. Major males of Neopantopsalis are distinguished from those of all other genera of Monoscutidae by the raised humps on the dorsal prosomal plate and the proventral row of greatly hypertrophied spines on leg I. Both major and minor males can be distinguished from representatives of other genera by the long, oblong, dorsoventrally flattened glans of the penis. Neopantopsalis is distinguishable from Monoscutinae by the unsclerotised and unornamented opisthosoma, and from Megalopsalis by the absence of a pedipalpal patellar apophysis. Spinicrus has the dorsal margin of the prosoma in front of the ocularium horizontal rather than sloping downwards, while the glans of its penis is short and triangular ( Hickman 1957). Species of Pantopsalis have the medial side of the pedipalpal patella and tibia more densely setose, and the glans of the penis is not dorsoventrally flattened ( Taylor 2004).

Description. MALE. Dorsal prosomal plate of major males with humps on either side and behind the ocularium at the boundary of the median and posterior propeltidial areas. Postocularium and mesopeltidium raised in major males to form third hump directly behind ocularium. Metapeltidium sclerotised medially to form round sclerotised area with dorsal prosomal plate. Chelicerae long and slender, with both segments evenly denticulate. Cheliceral fingers sinuous. Pedipalps without apophyses or heavily setose areas. Legs very long; leg I with longitudinal row of hypertrophied spines on proventral margin of femur; row of shorter stouter spines on dorsal margin, dwindling distad. Glans of penis long, dorsoventrally flattened. Bristle groups on the penis significantly reduced, particularly on left side.

Etymology. The name Neopantopsalis had been given to this genus by Glenn Hunt. Doubtless it was derived from the Greek prefix neo -, meaning new, and Pantopsalis , another genus of the Monoscutidae found in New Zealand ( Taylor 2004). The gender is feminine.

Comments. The current generic distinctions within Megalopsalidinae are very poorly defined. In his series of keys for Opiliones, Roewer (1923) effectively assigned any member of Phalangiinae from Australia or New Zealand to either Pantopsalis Simon 1879 or Megalopsalis Roewer 1923 (a new name for the preoccupied Macropsalis Sørensen 1886 ), depending on whether a pedipalpal patellar apophysis was present ( Megalopsalis ) or absent ( Pantopsalis ). Though Phillips & Grimmett (1932) considered the possibility that their M. fabulosa ( Phillips & Grimmett 1932) (described under Macropsalis ) from New Zealand might eventually be placed in a new genus, the Roewerian system remained in use ( Forster 1944). Forster (1949) identified the presence of ventral teeth on the tarsal claw of the pedipalp in Australian species, and therefore placed species previously included in Pantopsalis into a new genus, Spinicrus .

Many of the species currently assigned to both Megalopsalis Roewer 1923 and Spinicrus Forster 1949 are probably incorrectly so (C. Taylor, unpublished observations), and hence the differential diagnosis above refers to their type species only. Previously, the species assigned here to Neopantopsalis would have been assigned to Spinicrus due to the lack of a pedipalpal patellar apophysis. Despite the fact that only eight species have been assigned to it, Spinicrus as previously described includes a wide range of morphologies, and may not represent a coherent group. The only two defining characters established for this genus by Forster (1949) are absence of a pedipalpal patellar apophysis and presence of a ventral tooth-row on the claw of the pedipalp. The type species, S. tasmanicum , is very different from the taxa here placed in Neopantopsalis (see Hickman 1957), and it is felt that recognising the Neopantopsalis species as a separate genus better reflects their identity as a distinguishable group that is widespread in eastern Australia. The remaining species assigned to Spinicrus (see Taylor 2004 for a complete listing) do not show the entire suite of characters found in Neopantopsalis , and establishing their correct systematic position probably will not be possible without a thorough phylogenetic investigation of the Monoscutidae as a whole.

The species assigned to Neopantopsalis herein can be divided into three phenetically distinct groups, with the exception of Neopantopsalis continentalis whose identity is currently uncertain. Neopantopsalis camelus and N. thaumatopoios are most similar to one another, with femur II pseudoarticulated and numerous small denticles on the propeltidium. Neopantopsalis quasimodo is currently distinct from the other described species, with no pseudoarticulations in femur II, fewer and larger denticles on the propeltidium, and a more elongate glans than other species, but as yet undescribed species similar to N. quasimodo may also be present (see comments after the description for N. quasimodo ). Neopantopsalis pentheter and N. psile form a third group, also with no pseudoarticulations in femur II but with the propeltidium entirely or almost entirely unarmed. As well as the morphological distinction between these groups, there is also a clear geographical distinction ( Fig. 2 ). Neopantopsalis quasimodo is the northernmost species, and is found well north of the Tropic of Capricorn. Neopantopsalis pentheter and N. psile have a more southerly distribution, with that of N. psile near the coast of Queensland straddling the Tropic of Capricorn, and N. pentheter on the Queensland to New South Wales border. Neopantopsalis camelus and N. thaumatopoios are the southernmost species, being known from localities in northern New South Wales.

Figures

FIGURE 2. Localities of Neopantopsalis in north-eastern Australia: square with dot = N. quasimodo n. sp.; solid square = N. continentalis; circle with dot = N. psile n. sp.; solid triangle = N. pentheter n. sp.; triangle with dot = N. thaumatopoios n. sp.; solid circle = N. camelus.