The first native Pyrgodesmidae (Diplopoda, Polydesmida) from Australia

Abstract Three new genera and six new species of Pyrgodesmidae are described from Queensland: Asticopyrgodesmus gen. n., containing Asticopyrgodesmus lamingtonensis sp. n. and Asticopyrgodesmus maiala sp. n. (type species); Nephopyrgodesmus gen. n., with Nephopyrgodesmus eungella sp. n. (type and only species); and Notopyrgodesmus gen. n., with Notopyrgodesmus kulla sp. n. (type species), Notopyrgodesmus lanosus sp. n. and Notopyrgodesmus weiri sp. n. Localities and specimen data are given in an Appendix for undescribed Australian Pyrgodesmidae occurring in wet forests from the Northern Territory south to New South Wales, and on Lord Howe Island.


Introduction
Pyrgodesmidae were first reported from Australia by Black (1997), who listed 'Haplodesmidae and Pyrgodesmidae' in his table of millipede family occurrences in Australian regions. The identification seemed a little uncertain: "Members of the families Haplodesmidae and Pyrgodesmidae are difficult to distinguish from one another. They are small, highly sculptured and rigid-bodied animals, widespread in soil and litter" (Black 1997, p. 558).
Together with haplodesmids and pyrgodesmids, Black may also have been recording superficially similar species of Asphalidesmus Silvestri, 1910 (Dalodesmidea), which are locally common in eastern Australia from northern Queensland to Tasmania (Mesibov 2011). The identity and relationships of Asphalidesmus were unclear when Black prepared his overview of the Australian millipede fauna. Burrows et al. (1994) mentioned that a semi-aquatic polydesmidan, tentatively identified as a pyrgodesmid, had been collected on the campus of Macquarie University in Sydney, New South Wales in the early 1990s. The specimens were later identified as Aporodesminus wallacei Silvestri, 1904 (Pyrgodesmidae) by Adis et al. (1998), who published a redescription of this species. A. wallacei has also been reported from St Helena (southern Atlantic Ocean), Tahiti and the Hawaiian Islands (Adis et al. 1998). It is a good example of a cryptogenic species (Carlton 1996), as it is not known to be native anywhere in its range.
As recently as 2011, Pyrgodesmidae were thought to be "unknown from Australia" (Shelley 2011, p. 7). Native pyrgodesmids are, in fact, common and readily collected in the wet forests of Queensland, and Australian museums hold specimens of Pyrgodesmidae from ca 14°S in northern Queensland to ca 35°S in southern New South Wales, a north-south range of ca 2300 km ( Fig. 1; see Appendix for details of records). There are also Australian museum holdings of Pyrgodesmidae from the Northern Territory and Lord Howe Island (Fig. 1).
In this paper I sample the large diversity of native Australian pyrgodesmids by describing six new species from widely separated Queensland localities. I have redeposited as 'Pyrgodesmidae' another ca 400 specimens, representing an unknown number of additional species, in their respective Australian repositories (see Appendix). See the Discussion section for remarks on the taxonomic position of the three new genera described below.

Methods
'Male' and 'female' in the text refer to adult individuals. All specimens are stored in 75-80% ethanol in their respective repositories.
Gonopods were cleared in 80% lactic acid and temporarily mounted in 60% lactic acid for optical microscopy, while other body parts were temporarily mounted in a 1:1 glycerol:water mixture. Preliminary drawings were made from views at 160X on a binocular microscope. Photomicrographs were taken with a Canon EOS 1000D digital SLR camera mounted on a Nikon SMZ800 binocular dissecting microscope equipped with a beam splitter. Measurements were made with the same microscope using an eyepiece scale. Some of the photomicrographs in this paper are composites, generated by focus-stacking with Zerene Stacker 1.04 software. Specimens for scanning electron microscopy were briefly air-dried, temporarily fixed to a stub with double-sided adhesive tape, examined uncoated with a FEI Quanta 600 operated in low-vacuum mode, then returned to alcohol. Images and drawings were prepared for publication using GIMP 2.6. Maps were generated using ArcView GIS 3.2.
Hoffman (1976) proposed a system for naming some commonly observed features of pyrgodesmid sculpturing. From Hoffman's system I have taken the terms 'paramedian tubercles' and 'dorsolateral tubercles'; see the text below and the figure captions for details. In describing details of microsculpture I use the terminology of Akkari and Enghoff (2011b).
The Appendix contains specimen data for the museum lots of Australian Pyrgodesmidae I examined. Locality details there and in the text below are given in all cases with latitude and longitude based on the WGS84 datum. The uncertainty for each locality is the radius of a circle around the stated position, in metres or kilometres.
Midbody metatergite sculpture usually obscured by encrusted soil particles, patterned in 4 transverse rows of variably sized, rounded tubercles; enlarged paramedian or dorsolateral tubercles not evident on any rings (Fig. 4A). Anterior metatergal margins indistinctly divided into ca 16 lobes, posterior margin into 14 lobes, the lateralmost lobe on each side largest and most clearly demarcated. Paranota (Fig. 5A) very short, arising low on body, slightly declined, pitched so anterior margin is higher than posterior margin. Ring 2 paranotum expanded anterodistally, lateral margin weakly divided into 3 rounded lobes. From ring 3 onwards, anterior margin very slightly convex, undivided; 2 weakly demarcated lateral marginal lobes, the anterior lobe larger; posterior margin short, slightly convex.
Metatergal surface details obscured by soil particles and secretions; no setae evident on collum, tergites or metatergites. Prozonites with lozenge-shaped raised elements anterior to suture and subspherical knobs posterior to suture; suture marked by a ridge of longitudinally elongated elements. Limbus a single row of very thin lobes with more or less straight distal margins, and with 1-2 very thin spikes above each lobe (Fig. 2C).
Distribution. Rainforest in southeastern Queensland, from D'Aguilar National Park northwest of Brisbane almost to the New South Wales border, a north-south distance of ca 110 km (Fig. 11). Co-occurs with A. lamingtonensis sp. n. in Lamington National Park.
Etymology. For the Maiala section of D'Aguilar National Park, the type locality; noun in apposition.
Remarks. Two of the males in ANIC 64-000220 are noticeably smaller than the other seven in the sample, but seem to have the same gonopod structure in situ at high optical magnification. While the smaller 'A. maiala' specimens may represent a third species of Asticopyrgodesmus, I have not been able to detect differences in somatic features between them and the seven larger males in ANIC 64-000220. Males with head + 20 rings (females not yet recognised). Paranota (Fig. 5B) extending further laterally than in A. maiala sp. n., anterior edge lower than posterior edge, declined at ca 60°. Ozopores on porosteles on rings 5, 7, 9, 12, 15 only. Gonopod telopodite (Figs 7C, 7D, 8A) divided distally into three branches: (a) basal branch posteriorly directed, mediolaterally flattened, apically with broad, gently convex margin; (b) solenomere rod-like, medial, tapering to point, posteriorly directed at base and abruptly bent posterolaterally; (c) laterodistal branch directed posterolaterally, subdivided into two mediolaterally flattened processes directed posteriorly with wide, U-shaped gap between, the lateral process larger, both processes tapering to rounded apex.

Asticopyrgodesmus lamingtonensis
Distribution. So far known only from rainforest at the type locality in southeastern Queensland (Fig. 11). Co-occurs with A. maiala sp. n.
Etymology. For Lamington National Park, the type locality; adjective.
Remarks. This species very closely resembles A. maiala sp. n., but differs most obviously in ring number.
Diagnosis. Males and females with head + 20 rings; collum completely covering head in dorsal view; metatergal tubercles patterned in 3 transverse rows; paramedian and dorsolateral tubercles slightly enlarged; ozopores not on porosteles; gonopod telopodite divided distally into medial, flagellum-like solenomere and much larger lateral branch, the latter divided into appressed medial and lateral processes, with the solenomere normally lying parallel to and just above the line of contact between the two processes. Etymology.
Collum completely covering head in dorsal view (Fig. 3B); anterior margin of collum parallel to ground, weakly divided into 10 rounded lobes; main part of collum nearly perpendicular to ground in lateral view. Overall ring widths 2-17 about equal; rings 18 and 19 narrower.
Metatergal surface details obscured by soil particles and secretions; no setae evident on collum, tergites or metatergites. Prozonites with lozenge-shaped raised elements anterior to suture and subspherical knobs posterior to suture; suture marked by a ridge of longitudinally elongated elements. Limbus a single row of very thin lobes with more or less straight distal margins, and with 1-2 very thin spikes above each lobe (Fig. 2D).
Gonopore a small, inconspicuous opening on medial surface of leg 2 coxa. Aperture tranversely ovoid, between 1/3 and 1/2 width of ring 7 prozonite. Gonocoxa shallowly concave medially, forming gonocoel, with a few setae on outer ventromedial and inner dorsomedial surfaces, and with small, setose knob on medial surface near base. Telopodite (Figs 7E, 8B) arising on anteromedial surface of gonocoel, cylindrical near base, the distal two-thirds bent posterolaterally and divided into a large, complex, main branch and a flagellum-like, anteromedial solenomere. Main branch subdivided into lateral and medial portions; lateral portion slightly flattened mediolaterally, posterior margin expanded basally, anterior margin folded over medially; medial portion of main branch ca 2/3 length of lateral portion and narrower, apex acuminate, closely pressed to lateral portion, and with small, thin tab on medial surface directed posteromedially. Solenomere a little longer than medial portion of main branch, normally lying in groove between folded-over anterior margin of lateral portion of main branch and anterior margin of medial portion (Fig. 7E). Prostatic groove running on anteromedial surface of telopodite base before entering flagellum, apparently opening on flagellum tip. When retracted (Fig. 9C), gonocoxae forming two low, rounded mounds, the distomedial edges almost meeting anteriorly but separated posteriorly, exposing anterior surface of telopodite.
Distribution. Known from rainforest in the Eungella area in central (near-coastal) Queensland and from Finch Hatton Gorge, ca 15 km distant (Fig. 11).
Etymology. For Eungella National Park, the type locality; noun in apposition. The name Eungella is "Derived from [the] town and pastoral run name first used by Ernest Favenc (1845-1908), explorer, journalist and historian, in July 1876, reportedly an Aboriginal word, language and dialect not recorded, indicating land of cloud" (http://www.derm.qld.gov.au/property/placenames/details.php?id=46868; accessed 12 July 2012).
Remarks. N. eungella is one of the few Australian pyrgodesmids which can be found partly coiled in preservation (Fig. 9A).
Greek notos ('south') + the type genus of the family, Pyrgodesmus; gender masculine.  Diagnosis. Readily distinguished from N. lanosus sp. n. in having ozopores on porosteles on rings 5,7,9,10,12,13,15,16, and in lacking 'spines' (tight clusters of hair-like cuticular outgrowths) on the tips of the paramedian tubercles. Readily distinguished from N. weiri sp. n. in larger size (adults 9-10 mm in length vs 6 mm) and in the lack of a deep notch separating the lateral marginal lobes on the paranota.
Collum completely covering head in dorsal view (Fig. 3C); anterior margin of collum parallel to ground, weakly divided into 10 rounded lobes; main part of collum nearly perpendicular to ground in lateral view. Overall ring widths 2-17 about equal; rings 18 and 19 narrower.
Midbody metatergite sculpture sometimes obscured by encrusted soil particles, but clearly patterned in 2 transverse rows (Fig. 10A, B): 2 low paramedian tubercles; dorsum between paramedian tubercles with 2 anterior raised areas and triangular posterior raised area, apex of the latter pointed anteriorly; 2 (sometimes 3) low dorsolateral tubercles, the posterior tubercle largest, sometimes extending slightly beyond posterior margin of metatergite and set slightly more dorsal than anterior dorsolateral tubercle. A prominent, posterolaterally directed tubercle on posterior metatergal margin, just above paranotal base. Metatergite surface broken into complex but more or less regular mosaics of low raised areas between paramedian tubercles and dorsolateral tubercles, and between dorsolateral tubercles and posterior paranotal lobe. Posterior paramedian tubercles enlarged as apically rounded cones and directed posterodorsally on rings 17-19; ring 18 tubercles largest (Fig. 4D). Paranota (Fig. 5D) arising low on body, very slightly directed posteriorly, declined at ca 30°, pitched slightly so anterior margin is lower than posterior margin. Ring 2 paranotum expanded anterodistally, lateral margin very weakly divided into 3 rounded lobes. From ring 3 onwards, anterior margin straight, undivided; 2 lateral marginal lobes (ring 3 sometimes undivided); posterior margin with deep notch basally. Rings 18 and 19 paranota directed posterolaterally.
Metatergal surface details obscured by soil particles and secretions, but some margins with very small, hair-like cuticular outgrowths with expanded tips; no setae evident on collum, tergites or metatergites. Prozonites with lozenge-shaped raised elements anterior to suture and subspherical knobs posterior to suture; suture marked by a ridge of longitudinally elongated elements. Limbus a single row of very thin lobes with more or less straight distal margins, and with 1-2 very thin spikes above each lobe (Fig. 2E).
Distribution. Wet forest on Cape York Peninsula south to the Daintree area in tropical northern Queensland, a north-south distance of ca 350 km (Fig. 11). Cooccurs with N. weiri sp. n. in the McIlwraith Range.
Etymology. Acronym, noun in apposition, for the four Aboriginal clans who are traditional owners of the McIlwraith Range: Kaanju, Umpila, Lama Lama and Ayapathu (http://www.derm.qld.gov.au/parks/kulla-mcilwraith-range/culture.html; accessed 12 July 2012). KULLA is also the name of the national park located in the Range. Remarks. The specimens from the southern part of the N. kulla range (Fig. 10A) are mostly smaller (males ca 8 mm long, midbody overall width ca 1.5 mm) than those from the type locality and are less encrusted with soil particles. Paratypes. ANIC: 1 male, 1 female, 1 stadium 7 male, 1 stadium 7 female, details as for holotype, 64-000247.
Distribution. So far known only from rainforest at the type locality in tropical northern Queensland (Fig. 11).
Etymology. Latin lanosus ('woolly'), referring to the dense covering of fine, hairlike structures in this species; adjective. Male ca 6 mm long; ring 12: overall width 1.3 mm, overall width/prozonite width 2.4, maximum vertical diameter 0.6 mm. Paranota (Fig. 5F, 10D) divided laterally into anterior and posterior lobes by prominent notch; porostele-bearing posterior lobes distinctly shorter than anterior lobes on same ring. Paramedian tubercles conical, apically rounded, beginning ring 14 increasingly extended, the posterior tubercle taller and directed posterodorsally (Fig. 4F). No prominent tubercle on posterior metatergal margin above base of paranotum. Gonopods not significantly different in form from those of N. kulla sp. n., although proportionately smaller.  Distribution. So far known only from wet forest at the type locality on Cape York Peninsula, Queensland (Fig. 11). Co-occurs with N. kulla sp. n.
Remarks. Since N. kulla sp. n. and N. weiri co-occur, it is clear that mate recognition in these species depends in syntopy on factors, including body size, other than gonopod form.

Discussion
The prozonite sculpture found in the three new Australian genera (Figs 2F-H) is very similar to that illustrated by Akkari and Enghoff (2011b) for one species each in the pyrgodesmid genera Cryptocorypha Attems, 1907 and Cynedesmus Cook, 1895, namely irregular lozenge-shaped projections ahead of the suture and rounded, dome-like projections behind the suture, with the suture marked by a ridge of longitudinally extended projections. The new genera also have the lobe-and-spike style of limbus illustrated by Akkari and Enghoff (2011b) for a species of Cynedesmus, although in the Australian genera the number of spikes above a lobe on the lower part of the limbus can vary from one to two (e.g., Fig. 2C) on a single ring of a single individual. I have not checked the mandibles of any of the Australian species for the presence of a molar hook, a structure which may be diagnostic for Pyrgodesmidae (Akkari and Enghoff 2011a).
The diagnoses I give above for the three new Australian genera are only intended to distinguish one from the other, and will need to be substantially revised and expanded when the many other native Australian Pyrgodesmidae are described. The diagnoses are not intended for use in distinguishing Australian from non-Australian genera. A diagnosis of that kind would require more information on reliable generic characters and character states than is currently available for this millipede family, whose systematics is confused: With more than 170 described, mostly monobasic genera, the Pyrgodesmidae is a family in dire need of revisionary work. This is mainly due to the policy of relying mostly on conspicuous somatic characters for the definition of genera rather than on perhaps more reliable characters, such as gonopodal structures, which are more complex and comparatively more difficult to describe... Many other contemporary authors have commented on the lamentable state of pyrgodesmid taxonomy... (Akkari and Enghoff 2011a, p. 61) I also prefer not to speculate on evolutionary affinities by linking the new Australian genera with existing genera on the basis of shared character states which are unlikely to be genus-level synapomorphies, such as the collum covering/not covering the head in dorsal view and presence/absence of porosteles, or with character states known to vary at the species level (e.g. porostele formula in Notopyrgodesmus).
The new Australian genera, however, are clearly distinct from the four pyrgodesmid genera previously described from closely neighbouring landmasses, namely Pixodesmus Carl, 1926and Plethodesmus Carl, 1926from New Caledonia, and Evurodesmus Silvestri, 1920and Lobiferodesmus Silvestri, 1920 from Papua New Guinea. None of the new Australian species has the double transverse row of very large tubercles on the collum in Pixodesmus, the three clearly separated paramedian tubercles on posterior rings seen in Plethodesmus, or the combination of three transverse rows of metatergal tubercles and presence of porosteles in Evurodesmus. Lobiferodesmus and Asticopyrgodesmus are alike in having no paramedian tubercles and a collum not covering the head, but species of the former have short, stout gonopod telopodites, while the telopodites in the two Asticopyrgodesmus species are comparatively long and slender, although bent. The gonopod telopodites of the four other Australian species are also distinct from those described and illustrated for Pixodesmus, Plethodesmus and Evurodesmus, none of which have the flagellum-like solenomere of Nephopyrgodesmus eungella, or the leaf-like telopodite tip of the Notopyrgodesmus species.
Whether any of the native Australian pyrgodesmids can be accommodated in genera known from elsewhere in the world is a question which depends for its answer on the much-needed family-level revision.