Strophurus trux, Vanderduys, 2017

Vanderduys, Eric, 2017, A new species of gecko (Squamata: Diplodactylidae: Strophurus) from central Queensland, Australia, Zootaxa 4347 (2) : -

Strophurus trux sp. nov.

Golden-eyed geCko

( Figures 1 , 3–7 )

Material examined. Holotype: QMJ94287, male, Mt RedCliffe, 8 km south southwest of Marlborough, Central Queensland, Australia (149°53'30 E, 22°48'50" S), ColleCted by E. Vanderduys, 16 January 2015 . Paratypes: ColleCtion loCations as above. QMJ95523, female ColleCted by A. Reside and E. Vanderduys, 22 DeCember 2014; QMJ94284, male; QMJ94285, female; QMJ95524, male all ColleCted by E. Vanderduys, 16 January 2015.

Additional material: QMJ64068, female ColleCted by A. Melzer, 17 November 1997; Strophurus williamsi QMJ94286, male ColleCted by E. Vanderduys, 16 January 2015.

Diagnosis. Strophurus trux sp. nov. is a small (maximum SVL 48.8 mm), short-tailed (TL/SVL 0.47–0.61), faintly patterned or immaCulate geCko ( Figure 1 ) from Central eastern Queensland, Australia ( Figure 2 ). Strophurus trux sp. nov. Can be distinguished from all other Strophurus by the Combination of the following CharaCters: its bright yellow to riCh gold or golden brown Coloured iris ( Figure 3 ); its laCk of enlarged tuberCles or spines anywhere on the body exCept at the posterior edge of the upper eyelid; CloaCal spurs; generally dull pattern, with sCattered dark grey spots, eaCh oCCupying a single sCale at most, and sometimes a faint indiCation of slightly darker brown dorsal retiCulations, and often faint longitudinal stripes along the tail. Ventral surfaCe is demarCated from dorsal surfaCe along the lower sides, the ventral surfaCe being paler than the dorsal, usually with sCattered darker spots, eaCh oCCupying a single sCale. DemarCation of dorsal and ventral Colours is stronger on the tail than on the body. The mouth lining is pale blue while the tongue is pink to red ( Figure 4 ).

Description. Holotype: Detailed morphometriC and sCalation data are presented in Table 1. SCalation: rostral bordered above by 3 sCales (two large nasals and one granular internasal sCale); enlarged supraCiliaries only on upper, posterior edge of eyes; nares not in ContaCt with rostral; supralabials and infralabials progressively smaller posteriorly. General head sCalation of small CirCular to oblong granular sCales, forming hexagramiC patterns with neighbouring tiny sCales; eaCh larger granular sCale is bordered by six approximately equal sized neighbours and six tiny intergranules. The mental sCale is a blunt isosCeles triangle, 1.4 times wider than deep, bordered posteriorly by two granular sCales.

Head wide, long and distinCt from the neCk. Snout long, rounded when viewed from above, and angular at the level of the nares when viewed from the side. Eyes large with vertiCal pupil. Ear opening horizontally elliptiC on both sides. Trunk moderately robust and less than half the snout-vent length. General body, limb and tail sCalation is similar to head sCalation, with granular sCales larger ventrally than laterally and dorsally, but otherwise approximately equal in size throughout. Forelimbs and hindlimbs are moderately long relative to body length. Tail original, almost CylindriCal in Cross-seCtion, unbroken and slightly over half the snout-vent length. Clear evidenCe of nine internal Caudal glands present on the dorsal surfaCe of the tail, indiCated by a shallow, CresCent-shaped row of three to six sCales, immediately posterior to every fifth ring of Caudal sCales ( Figure 5 ). EvidenCe of tail glands not Clear on anterior and posterior ends of the tail, but slight sCale irregularities every fifth row suggest a total of 15 Caudal tail glands. Nine preCloaCal pores; four on the right, five on the left. CloaCal spurs present; rounded, three on the right, three on the left, though there is an even gradation between the enlarged CloaCal spurs and surrounding sCales, so this Count is open to some interpretation. There is a median Cluster of 15 enlarged preCloaCal sCales between the two hind limbs, just posterior to the preCloaCal pores and a median Cluster of enlarged sCales posterior to CloaCa at the base of the tail, over the hemipenal bulge.

Colour in life ( Figures 1 , 4 , 5 ): Dorsal Colour very faintly mottled pale grey with numerous darker spots peppering the baCkground Colour; these spots no larger than the sCales on whiCh they sit. Dorsal Colour fades gradually to Cream on the belly. Belly immaCulate, throat with very faint darker marbling. Tail Colour similar to the trunk Colour, but with a very slight blue-grey tinge to the dorsal surfaCe, and a moderately distinCt tonal demarCation between the upper and lower surfaCes, on the lateral margins of the tail. Eye Colour vivid lemon yellow around the periphery, tending towards a golden-brown around the pupil, whiCh is bordered by a white margin, numerous small white fleCks visible. Mouth lining pale blue. Tongue pink.

Colour in preservative ( Figure 6 ): Dorsal surfaCes grey with sparse, slightly darker spots. Darker spots are absent from the dorsal surfaCe of the head. Lateral and dorsolateral surfaCes are very faintly marbled with paler grey. Ventral surfaCe is Cream under the throat, trunk, and limbs. Faint darker stippling present under the throat. SubCaudal Colour tending towards very pale tan with distinCt demarCation between ventral and dorsal Colour along the lowers edges of the tail.

Paratypes: for morphometriC and sCalation data, see Table 1.

Colour in life ( Figure 7 ): Dorsal Colour similar to that of holotype, varying in number of single-sCale dark spots, and degree of baCkground marbling. Single sCale dorsal spots prominent in QMJ94284, QMJ95523 and QMJ95524, numerous but faint in QMJ94285, barely disCernible in QMJ94286.

Underside of throat with dark single-sCale spots in QMJ94284 and QMJ95524. One individual, QMJ95524 had more Contrasting pattern than all others. It had a ragged-edged, medial dark band running the length of the dorsal surfaCe, breaking up into faint, generally longitudinal retiCulations, on the tail. These retiCulations formed messy, broken stripes, inCluding pale laterodorsal stripes, a pale lower lateral stripe, bordered below by a faint, dark ventrolateral stripe ( Figure 7 (a)).

......continued on the next page Eye Colour is Consistent with that of holotype; vivid yellow to riCh golden brown around the pupil, whiCh is bordered by a white margin. Mouth lining also Consistent with holotype; pale blue with a pink tongue.

Etymology. The speCifiC epithet " trux " is Latin for wild, savage, harsh and pitiless, inCluding instruments of human savagery, and also of the sCene of suCh Cruelty ( Lewis & Short 1879; Glare 1982). This name was Chosen in referenCe to the only loCation known for Strophurus trux sp. nov. It is in the proximity of the "Marlborough stretCh", a seCtion of the old BruCe Highway in Central Queensland with notoriety as a wild and dangerous plaCe in the 1960s and 1970s beCause of a series of murders and shootings ( Gibson 2002) and its general remoteness.

Comparison with other species. Strophurus trux sp. nov. is most similar to Strophurus congoo , from whiCh it differs in having bright yellow to golden irises (versus a Cream baCkground with brown to orange retiCulum in S.

congoo ). Like S. congoo , in S. trux sp. nov. the dorsal and lateral sCales are homogenous in size throughout, and there are sCattered darker grey to blaCk spots that oCCupy a single sCale eaCh over muCh of the dorsal and lateral surfaCe and on the upper surfaCes of the limbs. The mouth lining is blue, as in S. congoo , while the tongue is more pink–maroon (versus dark blue-blaCk to brown in S. congoo ), though any distinCtion between the two speCies by these CharaCters is lost in the preserved material. The known ranges of S. trux sp. nov. and S. congoo are separated by ~ 780 km ( Figure 2 ).

CharaCters provided in Vanderduys (2016) that Compare Strophurus congoo with all other Strophurus are similarly useful in distinguishing S. trux sp. nov. from all other Strophurus (exCept S. congoo , see above) and highlight the similarity between S. trux sp. nov. and S. congoo . These CharaCters are not Covered exhaustively here, but are summarised below.

Strophurus trux sp. nov. laCks any form of enlarged spines or tuberCles, with the exCeption of postoCular supraCiliaries whiCh are usually enlarged into 2–4 short spines on either side, and enlarged CloaCal spurs. In this, it differs from the "spiny-tailed" ( Wilson & Swan 2013) Strophurus ; S. assimilis , S. ciliaris , S. intermedius , S. krisalys , S. rankini , S. spinigerus , S. strophurus , S. wellingtonae and S. williamsi . With a maximum reCorded SVL of 48.8 mm, S. trux sp. nov. is also signifiCantly smaller than any of these speCies.

From the seven "striped" or "phasmid" geCkos ( Wilson & Swan 2013; Oliver & Parkin 2014); S. jeanae , S. mcmillani , S. michaelseni , S. robinsoni , S. taeniatus , S. wilsoni , and S. horneri , S. trux sp. nov. differs in laCking a Clear pattern of longitudinal stripes. At most, any stripes present in S. trux sp. nov. are messy and faint ( Figure 7 (a and b)). Male S. trux sp. nov. further differ from these in possessing preCloaCal pores, though the laCk of preCloaCal pores is only inferred for S. horneri ( Oliver & Parkin, 2014, and referred to as "post-CloaCal", whiCh is assumed here to be in error).

From Strophurus elderi , S. trux sp. nov. differs in its finer build (versus robust), generally dull patterning (versus possessing dark edged, Cream to white spots) and the males possessing preCloaCal pores (versus absent in S. elderi ).

From Strophurus taenicauda , S. trux sp. nov. differs in its muCh smaller adult size, generally dull patterning (versus starkly Contrasting blaCk spots and patChes on a pale grey to white baCkground, and an orange to gold dorsal tail stripe).

The Combination of iris pattern and Colour alone are suffiCient to distinguish S. trux sp. nov. from most other Strophurus . From all Strophurus exCept S. michaelseni , some S. spinigerus and S. taenicauda triaureus , S. trux sp. nov. differs in its eye Colour whiCh is yellow–golden brown, with a few white fleCks within it. Both S. spinigerus spinigerus (Gray) and S. s. inornatus (Storr) usually have a dark maroon area surrounding the pupil ( Storr, 1988), whiCh is more subtle or only vaguely present in S. trux sp. nov. ( Figure 3 ). Several other Strophurus ( S. ciliaris , S. intermedius , S. rankini , S. strophurus , S. wellingtonae and S. williamsi ) may have bright yellow to gold eyes, but the pupil is prominently surrounded by blaCk or dark brown retiCulations on a white baCkground.

Where S. williamsi oCCurs in Close sympatry to both S. trux sp. nov. and S. congoo the dorsal tuberCles of S. williamsi , though present, tend to be reduCed ( Vanderduys 2016), see Figure 8 .

Initial genetiC analyses based on mitoChondrial data alone suggest that S. trux sp. nov. sits within the S. strophurus lineage of Nielsen et al. (2016), but no Close relationship with any other lineages in this group is strongly supported (Oliver, pers. Comm.). The presenCe of preCloaCal pores in males of this group also suggests that it fits within the S. strophurus lineage.

Figures

FIGURE 1. Holotype QMJ 94287 male Strophurus trux sp. nov. showing the scattered peppering of dark grey to black spots and faint reticulations on the dorsal surface. Also clearly visible is the relatively clear demarcation of tone along the lateral surface of the tail.

FIGURE 2. Map showing collection location of all known Strophurus trux sp. nov. specimens, plus S. williamsi QMJ 94288 (main map; circled area). Hatched area is an estimated minimum area of occupancy, based on Regional Ecosystem classification and field observations of habitat type. Locations of other Strophurus (both S. williamsi) are shown with QM acquisition numbers. Cross to the southwest of Cairns on the inset map indicates location of Strophurus congoo, 780 km to the north west of S. trux locality.

FIGURE 3. Bright yellow to golden-brown eyes of Stropurus trux sp. nov. which lend it the common name golden-eyed gecko; QMJ 94285 above, QMJ 95524 below.

FIGURE 4. Holotype QMJ 94287 Strophurus trux sp. nov. showing blue mouth lining and pink tongue typical of the species.

FIGURE 5. Dorsal surface of tail of holotype QMJ 94287 Strophurus trux sp. nov. in life, showing locations of nine caudal glands. Inset is enlarged section showing locations of glands two to four, with number three highlighted to give more definition.

FIGURE 6. Holotype QMJ 94287 male Strophurus trux sp. nov. in preservative.

FIGURE 7. (a) Male QMJ 95524 showing bolder markings than other specimens; (b) female QMJ 95523; (c – d) male QMJ 94284.

FIGURE 8. Male Strophurus williamsi QMJ 94288 collected 235 m from S. trux sp. nov. QMJ 94287, showing distinguishing features where the two species are sympatric; orange eyes with the pupil surrounded by a black over white reticulum, relatively bold dorsal pattern, enlarged orange tubercles on dorsal and caudal surfaces.