Saltuarius eximius, Hoskin, Conrad J. & Couper, Patrick, 2013

Hoskin, Conrad J. & Couper, Patrick, 2013, A spectacular new leaf-tailed gecko (Carphodactylidae: Saltuarius) from the Melville Range, north-east Australia, Zootaxa 3717 (4), pp. 543-558 : 545-553

publication ID	https://doi.org/ 10.11646/zootaxa.3717.4.6
publication LSID	lsid:zoobank.org:pub:1E052509-825D-4527-8F24-1F1C7781C47B
DOI	https://doi.org/10.5281/zenodo.6147899
persistent identifier	https://treatment.plazi.org/id/7820060E-FFD2-C23E-ACA0-FEB7B7CFFF69
treatment provided by	Plazi
scientific name	Saltuarius eximius
status	sp. nov.

Treatment

Saltuarius eximius sp. nov.

Cape Melville Leaf-tailed Gecko ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 , 3 View FIGURE 3 , 4 View FIGURE 4 A, 5A, 6, 7)

Material examined. Holotype: QMJ92377, female, Melville Range (14°16'38" S, 144°29'28" E, elevation 500 m), Cape Melville National Park, north-east Queensland, C. J. Hoskin, 20 March 2013. Paratypes: QMJ92378 (male), QMJ92379 (female), collection details as for holotype.

Diagnosis. Saltuarius eximius sp. nov. is highly distinct in its long and slender form, short head and very large eyes ( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 ). Saltuarius eximius sp. nov. is readily distinguished from all its congeners by the following nonoverlapping (or largely non-overlapping) body measurements (as % SVL): its more elongate and narrow body form (AG = 49–50% vs 40–51% combined range for all other Saltuarius species; midBW = 11–12% vs 13–21%); longer limbs (L1 = 55–57% vs 42–52%, L2 = 63–64% vs 52–63%); narrower neck (NW = 6.3–6.5% vs 7.5–10.7%); narrower head (HW = 18–19% vs 19–24%); shorter head (HL = 24–25% vs 25–30%); shorter temporal region (EE = 6.0–7.8% vs 7.4–10.3%); and larger eye diameter (ED = 7.8–8.6% vs 5.2–7.3%) (Table 1). Saltuarius eximius sp. nov. also has an unpatterned grey eye versus the patterned eyes of all congeners. Saltuarius eximius sp. nov. also has a distinct tail that is elaborately frilled along the margin with a short, fine attenuated tip.

Etymology. Eximius ; from the Latin meaning exceptional, extraordinary, exquisite. In recognition of the particularly fine form and distinctiveness of this species. The species epithet is treated as a noun in apposition.

Measurements and scale counts of holotype. SVL = 106.4 mm, AG = 53.5 mm, midBW = 11.5 mm, Tail (original) = 68.3 mm, Tip = 17.2 mm, TailW = 33.9, L1 = 60.7 mm, L2 = 68.6 mm, FLL = 26.3 mm, HLL = 28.6 mm, HL = 25.8 mm, HW = 19.7 mm, snout = 11.8 mm, EE = 6.4 mm, ED = 9.2, NL = 20.8 mm, NW = 6.7 mm, enlarged lamellae 4th finger = 19, enlarged lamellae 4th toe = 18, lamellae to junction 3rd and 4th finger = 19, lamellae to junction 3rd and 4th toe = 21 (includes 3 smaller scales at basal end), supralabials = 15 (1st in series fused), infralabials = 12.

Description of type series ( Fig. 6 View FIGURE 6 ): Data presented as range followed by mean in brackets. Adult measurements (mm): SVL 106.4–118.3 (112.4); AG 53.5–58.3 (55.6); midBW 11.5–14.4 (13.2); Tail (original) 68.3 (only holotype has an original tail); Tip (original) 17. 2; TailL 53.1–68.3 (59.7); TailW 33.9–41.2 (37.3); L1 60.7–65.3 (62.5); L2 68.6–74.5 (71.2); FLL 26.3–30.5 (28.3); HLL 28.6–31.5 (29.9); HL 25.8–29.1 (27.5); HW 19.7–22.3 (21.2); snout 11.8–13.2 (12.5); NW 6.7–7.6 (7.2); NL 20.8–22.4 (21.8); EE 6.4–9.3 (7.8); ED 8.8–9.5 (9.1). Adult proportions: see Table 1. Head: Short, deep, triangular, distinct from neck; head depth 48–53% of head TABLE 1. Morphological comparison of S. eximius sp. nov. with other Saltuarius species and Orraya occultus . Table shows data for SVL (mm) then length of traits as a proportion (%) of SVL. Mean is presented above range. Ranges for traits with proportions over 10% are rounded to nearest percent. For S. eximius sp. nov. and O. occultus , only a single specimen had an original tail, while for S. kateae , no specimens with original tails were available. Morphology codes are: SVL: snout to vent length, Tail: original tail length, Tip: original tail tip length, AG: axilla to groin length, midBW: mid–body width, L1: forelimb length, L2: hindlimb length, HL: head length, HW: head width, snout: snout length, NW: neck width, NL: neck length,

: eye to ear distance, ED: eye diameter. For more details see Methods. For S. eximius sp. nov. the data comes from the three specimens comprising the type series. For the other species, the data is a summary of measurements taken from the specimens listed in the Appendix and data from Couper et al. (2008) and Couper et al. (1993).

SVL Tail/SVLTip/Tail AG/SVLmidBW/ L1/SVL L2/SVL HL/SVL HW/SVL snout/ NW/SVL NL/SVL EE/SVL ED/SVL SVL SVL

eximius sp nov. 112 64.1 25.2 49.5 11.7 55.6 63.4 24.5 18.8 11.1 6.4 19.4 6.9 8.1 106–118 49– 50 11–12 55–57 63–64 24– 25 18–19 11–11 6.3–6.5 19–20 6.0–7.8 7.8–8.6 cornutus 126 63.2 35.8 45.5 16.2 47.8 56.9 28.1 21.8 13.5 9.4 17.8 9.3 6.3 116–136 59–68 32–40 41–49 13–19 47–51 55–61 27–29 21–22 13–14 8.9–9.8 15–21 8.6–10.0 5.6–7.2 salebrosus 132 63.9 25.6 44.6 17.7 47.3 55.5 26.6 22.7 12.3 9.4 19.6 9.7 5.8 121–144 58–72 22–30 43–47 14–21 45–51 52–61 26– 27 22–24 12–13 8.8–10.7 18–21 9.3–10.0 5.2–6.5 swaini 124 66.9 40.6 46.2 15.9 48.2 58.7 26.2 20.4 12.2 8.9 18.6 8.3 6.1 99–134 59–72 35–49 41–51 15–17 44–51 53–62 25– 29 19–22 11–14 8.0–9.6 15–22 7.4–9.4 5.6–6.5 wyberba 99 71.2 40.6 45.0 17.1 47.2 57.4 27.3 22.1 12.1 9.8 17.7 8.9 7.0 86–108 62–81 33–46 40–48 16–18 44–51 53–63 25– 29 20–24 11–14 8.3–10.6 15–21 7.5–10.0 6.6–7.3 kateae 104 46.8 17.8 46.3 58.0 27.2 21.3 12.2 8.3 17.4 8.3 6.4 97–110 45–48 17–19 45–47 55–60 27– 28 21–22 12–13 7.5–8.7 15–20 7.5–9.2 6.3–6.6 moritzi 98 68.9 39.3 45.1 16.7 47.4 57.7 26.9 21.2 12.2 9.1 19.4 8.4 6.8 88–109 63–76 29–47 40–50 15–19 42–52 52–62 25– 30 20–24 11–14 8.3–10.6 16–23 7.4–10.3 6.4–7.1. occultus 103 48.4 21.5 43.4 15.9 47.1 59.0 25.8 17.2 13.0 6.7 24.2 6.9 6.5 95–108 41–45 13–18 45–49 56–61 25– 27 16–19 12–14 6.1–7.2 23–27 6.3–7.3 5.6–7.2 width (mean = 50%); covered in small granules which are intermixed with larger conical tubercles; skin of head coossified with skull; rostral much broader than tall ( Fig. 2 View FIGURE 2 ), fully divided by a single medial groove ( Fig. 2 View FIGURE 2 ); rostral shield in contact with nostril ( Fig. 2 View FIGURE 2 ); 5–6 scales bordering dorsal edge of rostral scale (mean = 5.3); ear opening elliptical, vertical, ~ ¼ as large as eye; supralabials 14–15 (mean = 14.3); infralabials 12. Neck: Distinct and narrow, with large, sharp-tipped tubercules on dorsum. Body: Narrow and elongate, covered in small granules; dorsal granules intermixed with larger conical, sharp-tipped tubercles; tubercles largest on back and upper flanks, and generally arranged as longitudinal rows ( Fig. 2 View FIGURE 2 ); ventrolateral skin fold with a row of small, bluntly tipped tubercules; medial scales on belly considerably larger than the small outer granules that lie adjacent to the ventrolateral skin fold; a patch of enlarged, centrally placed scales is present in both the pectoral and pelvic regions; preanal pores absent in males; armpit with two pronounced skin flaps that form a pocket enclosing the axillary region ( Fig. 6 View FIGURE 6 ), the lower of which is continuous with the ventrolateral fold. Limbs: Long and slender, covered in pronounced pointed tubercles dorsally; digits long and strongly compressed distally; enlarged subdigital lamellae 4th finger 19–21 (mean = 20); dorsal surface of fingers without enlarged conical tubercles extending along digits; enlarged subdigital lamellae 4th toe 18–20 (n = 3, mean = 19.3); dorsal surface of toes with enlarged conical tubercles on basal portion of all digits except the first digit; subdigital scales from tip of 4th finger to junction of 3rd and 4th fingers 19; subdigital scales from tip of 4th toe to junction of 3rd and 4th toes 21–22 (mean = 21.7). Original tail (holotype only; Fig. 3 View FIGURE 3 ): Broadly flared with an elaborate, undulating (‘frilled’) outer flange, and a short, fine attenuated tip; outer frill edged with small sharp spines; attenuated tip with very small spines on first 2/3rds of its length. Regenerated tail (paratypes; Figs. 1 View FIGURE 1 , 6 View FIGURE 6 ): Broadly flared and paddle-shaped, ‘pinched-in’ about 1/3rd of the way along its length and with a broadly rounded posterior margin. Colour pattern in preservative ( Fig. 6 View FIGURE 6 ): Dorsal base colour grey to tan, overlain with dark grey/brown markings. Head: Predominantly grey to tan; dark nuchal band in the supraoccipital region; labials pale with two broad dark bars (one at mid-snout, the other below the anterior orbit); dorsal surface of snout bridged by a series of dark chevrons; a dark, deep, V-shaped marking extending back medially between eyes. Body: Flanks with bold, dark mottling; dorsum with dark chevrons that merge with flank pattern and enclose four to five pale blotches between the pectoral and pelvic regions. Original tail (holotype): Alternating dark and light bands; basal region with two broad, poorly defined, pale bands and three broad dark bands; attenuated tip with two pale bands (anterior-most widest) and one dark band. Regenerated tail (paratypes): Pale with heavy dark grey and brown mottling. Limbs and digits: Pale, with bold, well-defined, dark bands. Ventral surfaces: Chin, throat and trunk off-white with obscure brown mottling; limbs pale, peppered with dark flecks; original tail has broad dark and pale bands (dark bands are continuous with those on the dorsal surface but each is split in two; Fig. 3 View FIGURE 3 ); regenerated tail mottled (less pronounced than on dorsal surface), with a paler central region.

Measurements of live individuals: Four adults were measured in the field. Measurements of the holotype (QMJ92377) in life were: SVL 109 mm, WT 16 g. Measurements for paratype QMJ92378 were: SVL 120 mm, WT 22 g. Snout to vent lengths of two individuals that were not collected were: 118 mm and 119 mm.

Colour pattern in life ( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 ): Dorsal colour an even mix of pale and dark markings; in some individuals this is a mix of white/pale grey and dark grey/black markings, while in others this is a mix of creamy brown and dark brown markings. Prominent markings include the following: a dark V behind the eyes; five pale bands along the back, with smaller pale markings in between; pale bands along the legs and fine pale bands on the digits; two broad, pale bands on the original tail and two white bands on the attenuated tail tip; and dark mottling on the regenerated tails. The iris is grey, tinged with yellowish green. Ventral surface is white but finely mottled with brown; underside of original tail white with soft brown bands; underside of regenerated tail pale in center but heavily mottled towards margin.

Comparison. Saltuarius eximius sp. nov. is a slender, long-bodied, long-legged, small-headed, large-eyed, large-tailed gecko which differs from all other Australian leaf-tailed geckos ( Orraya , Phyllurus and Saltuarius ) in the following ways. It is distinguished from Orraya (which it most resembles in general body form; Fig. 4 View FIGURE 4 ) in possessing two lumbar vertebrae (vs three in Orraya ) ( Fig. 7 View FIGURE 7 ); by the shape of the cervical vertebrae (marginally elongated vs distinctly elongated in Orraya ) ( Fig. 7 View FIGURE 7 ); by the size of the preanal pores (male preanal pores very small vs greatly enlarged in Orraya ); by the shape of the original tail (very large and broadly flared with a fine attenuated tip vs small and leaf-shaped in Orraya ); and by the spinosity of the regenerated tail (smooth-edged vs enlarged spines along margin in Orraya ) ( Figs 1 View FIGURE 1 C, 4C). Saltuarius eximius sp. nov. is further separated from Orraya in having a longer and narrower body, longer limbs, a shorter head and snout, a shorter neck, and larger eyes (non-overlapping differences, Table 1; Figs 4 View FIGURE 4 , 5 View FIGURE 5 ). Saltuarius eximius sp. nov. differs from Phyllurus in that the rostral contacts the nostril (vs nostril not in contact with rostral in Phyllurus ), male preanal pores are present (vs absent in Phyllurus ), and the original tail is strongly flared with an elaborate spinose outer flange (vs without elaborate outer flange in Phyllurus ). Saltuarius eximius sp. nov. is distinguished from all Saltuarius species in having a longer and more slender body, longer limbs, a shorter and narrower head, a shorter snout, a shorter temporal region, a narrower neck, and larger eyes (Table 1). Saltuarius eximius sp. nov. also differs from all congeners in having an unpatterned grey eye (vs patterned) ( Fig. 5 View FIGURE 5 ). It is most closely related to S. cornutus ( Figs 4 View FIGURE 4 B, 5B) and S. salebrosus , with which it shares preanal pores in males. In addition to the aforementioned traits, Saltuarius eximius sp. nov. is also smaller than both these species (max SVL = 118 mm vs 136 mm in S. cornutus and 144 mm in S. salebrosus ). Saltuarius eximius sp. nov. is further distinguished from the southern ‘ S. swaini ’ species group in that the males possess preanal pores (vs preanal pores absent in S. swaini , S. wyberba , S. kateae and S. moritzi ). Saltuarius eximius sp. nov. does not co-occur with any other leaf-tailed gecko.

Genetics. 12S/cyt- b mtDNA data places S. eximius sp. nov. as a divergent (9.1%) sister-species to S. cornutus (Hoskin, unpub. data). 12S and cyt b sequences for two individuals are deposited on GenBank (12S: QMJ92378 = KF553907 View Materials , QMJ92379 = KF553908 View Materials ; cyt b: QMJ92378 = KF553909 View Materials , QMJ92379 = KF553910 View Materials ).

Distribution. Known only from the vicinity of the type locality in the uplands of the Melville Range, Cape Melville, north-east Australia ( Fig. 8 View FIGURE 8 ). The distribution falls within Cape Melville National Park.

Habitat and habits. Six individuals have been found, all in close proximity in an area of granite boulders covered by a rainforest canopy ( Fig. 9 View FIGURE 9 ). Saltuarius eximius sp. nov. was not found in searches of other areas of rocky rainforest in the general vicinity of the type locality or in a lowland area of Cape Melville to the south (14°18'54" S, 144°29'54" E). Nor was the species found in searches of exposed boulder-fields in the vicinity of the type locality (as seen in the background of Fig. 9 View FIGURE 9 A). At the type locality, individuals were found at night on vertical surfaces of boulders or trees, between one and five meters above the ground. When first sighted the geckos were motionless and positioned head-down, with the anterior half of their body raised well off the surface and their head held parallel with the surface. In this foraging pose, S. eximius sp. nov. is no doubt primarily a sit-and-wait predator like other leaftail geckos. Several of the geckos made an extended squeaking sound when first captured. The only other gecko species found in micro-sympatry with S. eximius sp. nov. was Cyrtodactylus tuberculatus (Lucas & Frost 1900) , which was present at higher abundance. Two frog species, Litoria andiirrmalin McDonald 1997 and Cophixalus zweifeli Davies & McDonald 1998, were also found foraging at night at the site.