Amalosia nebula, Hoskin & Couper, 2023

Hoskin, Ad. J. & Couper, Patrick J., 2023, Revision of zigzag geckos (Diplodactylidae: Amalosia) in eastern Australia, with description of five new species, Zootaxa 5343 (4), pp. 301-337 : 322-324

Amalosia nebula sp. nov.

Upland Zigzag Gecko

( Figures 17–19 )

Material examined. Holotype. Male, QM J91178 ( Fig. 17 ), Windsor Tableland, western side (16° 13’ 51” S, 144° 58’ 49” E), field collection code: conx5021, C. J. Hoskin, 26/8/2011 . Paratypes. (all localities in north-east Queensland) QM J91176 , J91177 , Windsor Tableland , western side (16° 13’ 51” S, 144° 58’ 49” E) ; J87069 Mount Windsor NP (16° 18’ 09” S, 145° 05’ 28” E) ; J92239, J92240, J92241, Carbine Tableland, near Mt Lewis (16° 36’ 07” S, 145° 15’ 47” E) ; J88666, Hann Tableland NP, near radar station (16° 54’ 39” S, 145° 15’ 16” E) ; J88685, Hann Tableland NP, near radar station (16° 54’ 45” S, 145° 15’ 19” E) ; J88684, Hann Tableland NP, near radar station (16° 54’ 47” S, 145° 15’ 23” E) ; J91317, Walsh’s Pyramid, near Cairns (17° 06’ 54” S, 145° 47’ 43” E) ; J97580, J97586, J97588–89 Herberton Range (17°20’ 32” S, 145°25’ 22” E) ; J78233, State Forest 511, via Ravenshoe (17° 36’ 25” S, 145° 28’ 12” E) ; J92261, Kahlpahlin Rock trail, Lamb Range (17° 55’ 00” S, 145° 37’ 15” E) .

Diagnosis. A moderate sized (max. SVL ~ 58 mm), relatively short-bodied (AG/SVL 0.40–0.49) and long-tailed (oTL/SVL 0.83–1.05) member of the A. rhombifer group. Dorsal pattern an irregular, deeply notched, pale vertebral zone, bordered by dark edging. The dark dorsolateral points are often in close proximity to those on the opposite side, serving to exaggerate the zigzag effect, and they sometimes join to form dark transverse bands (particularly over the nape, shoulders or hip). Little to no webbing between third and fourth toes. Males with 2–4 (usually 3), large, pointed, postcloacal spurs (small and rounded in females) and 2–7 precloacal pores, with a narrow to moderate pore gap (1–5 scales).

Measurements and scale counts of holotype: SVL 49.3 mm, rTL 40.3 mm, oTW 5.0 mm, oTD 4.1 mm, HL 10.8 mm, HW 8.6 mm, HD 4.4 mm, S 4.4 mm, AG 21.5 mm, L1 13.8 mm, FL 5.8 mm, L2 17.6 mm, LHL 7.1 mm, BW 9.0 mm, rostral crease 50%, scales contacting dorsal margin of the rostral 3, scales bordering nasal opening 6, scales contacting posterior margin of mental shield 6, supralabials 9, 2 nd supralabial taller and wider than 1 st supralabial, infralabials 9, postcloacal spurs 3, precloacal pores 2, pore gap 5, subdigital lamellae 4 th finger 6, subdigital lamellae 4 th toe 7, no webbing between 3 rd and 4 th toes.

Description of type series. Measurements ( Table 2). SVL (mm): 46.4–58.0 (n = 16, mean = 52.3). Proportions as % SVL: oTL = 83–105 (n = 5, mean = 95); HL = 20–23 (n = 16, mean = 22); HW = 16–17 (n = 16, mean = 17); HD = 6.8–10.1 (n = 16, mean = 8.7); S = 8.6–10.2 (n = 16, mean = 9.4); AG = 40–49 (n = 16, mean = 46); L1 = 26–30 (n = 16, mean = 28); L2 = 33–38 (n = 16, mean = 35); FL = 10–12 (n = 16, mean = 11); LHL = 13–16 (n = 16, mean = 14); BW = 15–21 (n = 16, mean = 17). Head. Narrow, elongate, distinct from neck; head width 71–82 % head length (n = 16, mean = 77); head depth 40%–61% head width (n = 16, mean = 53); snout length 41%–46% head length (n = 16, mean = 43); covered in small granules with slightly larger granules on the dorsal and lateral surfaces of the snout; rostral approximately twice as wide as deep, partially divided vertically by a medial groove extending 50–70% rostral height; 2–5 scales contacting dorsal margin of the rostral, lying between the nostrils (n = 17, mode = 3, mean = 2.8); 5–6 scales bordering nasal opening (n = 17, mode = 5, mean = 5.4); supralabials 8–12 (n = 17, mode = 9, mean = 9.9), 1 st and 2 nd supralabials usually subequal in width; 1 st supralabial taller than 2 nd supralabial or 1 st and 2 nd supralabials subequal; infralabials 9–12 (n = 17, mode = 11, mean = 10.3); 3–7 scales contacting posterior margin of mental shield, between 1 st infralabials (n = 17, mode = 5, mean = 4.9). Neck. Broad. Body. Slender, slightly depressed, covered in small granules; granules on ventral surface noticeably larger than those on dorsum; a row of enlarged postcloacal spurs (2–4, n = 17, mode = 3, mean = 3) behind the lower posterior margin of the thigh in both sexes (significantly larger and more pointed in males). 2–7 (n = 7, mode = 2, mean = 3.6) precloacal pores present in mature males, not extending to underside of thigh, and divided medially by 1–5 granular scales without pores (n = 7, mode = 5, mean 3.7). Limbs. Moderate length; digits dorsoventrally compressed and expanded distally; an enlarged pair of apical lamellae followed by a transverse series, divided distally, single proximally; forelimb with 5–8 enlarged lamellae on 4 th finger (n = 17, mode = 6, mean = 6.4), 3–4 split or deeply grooved; hindlimb with 6–9 enlarged lamellae on 4 th toe (n = 17, mode = 7, mean = 7.1), 3–5 split or deeply grooved; basal webbing usually absent between 3 rd and 4 th, minimal when present. Original tail. Moderately long (83–105% SVL), narrow (oTW/oTL = 9–11%), tapered, and slightly to moderately flattened (oTW/oTD = 107–163%) ( Table 2); scales arranged in concentric rings, slightly larger ventral surface. Pattern in spirit. Dorsal view. Head and body grey to mid-brown with a pale vertebral zone and a darker, zigzag, dorsolateral pattern. A diffuse dark, or pronounced, dark patch is present on the crown and a dark, central stripe is present on the dorsal surface of the snout. A dark facial stripe, beginning on snout and continuing behind eye, joins the dark zigzag dorsolateral zone, which has a narrow, dark upper edge and extends to the tip of the tail (original). A narrow dark band is often present on the nape. The zigzag pattern consists of dark points extending into the pale vertebral zone (7–10 between, and including, the pectoral and pelvic girdles). These may be either aligned or misaligned, so that the tip of each point aligns with the pale, point interspace on the opposite side. The vertebral zone may be clean or broken into blotches where the dark dorsolateral points come together, contacting on the vertebral line. In many specimens, there is close proximity between the left and right point tips, serving to exaggerate the zigzag effect and significantly narrow the pale vertebral zone. Flanks. A broad, dark zone that is peppered with small pale spots. Larger pale spots are also contained within some of the dark dorsolateral points. Original Tail. Pattern as for dorsum. Limbs. Variegated and with numerous pale spots. Ventral surface. Pale, unpatterned, off-white. Colour pattern in life ( Fig. 18 ). As described above but paler markings light grey or white (vs cream coloured in preservative) and darker markings shades of grey (vs often more brownish in preservative). White flecks on the lateral and dorsolateral surfaces more obvious in life. Iris dark copper or brown.

Comparisons. For comparison to A. hinesi sp. nov., see that description above. Distinguished from the other two southern Queensland species ( A. jacovae and A. lesueurii ) by no, or minimal, toe webbing (vs moderate–pronounced; Tables 1 , 2), low number of precloacal pores in males (0–7 vs A. jacovae 13–22, A. lesueurii 7–13), pale dorsal pattern dark-edged and deeply notched (vs broader and more diffuse in A. jacovae ), and limbs with minimal spotting (vs obvious spotting in A. lesueurii ). For comparison to A. saxicola sp. nov., see that description above. Amalosia nebula sp. nov. differs from A. queenslandia sp. nov., A. capensis sp. nov. and A. cf. rhombifer by its larger size (mean SVL 52 mm vs 45 mm, 45 mm, 47 mm, respectively; Table 2; Fig. 19 ), more robust form (e.g., Fig. 19 ), and irregular, deeply notched dorsal pattern, often with a narrow cross-bar across the nape, shoulders or hips (vs more evenly broad, regular in zigzag edge, and rarely broken in the other species). It also differs from these species in having fewer precloacal pores (mean 3.6 vs A. queenslandia sp. nov. 8.5, A. capensis sp. nov. 17.1, A. cf. rhombifer 16.9; Table 2), in having a larger gap in the precloacal pore series than A. queenslandia sp. nov. (mean 3.7 scales vs 1.0; Table 2), and in having more postcloacal spurs than A. cf. rhombifer (usually 3 vs usually 2; Table 2).

Genetic data. Two ND4 sequences deposited on GenBank: OM523367 (specimen: QM J91178 ; holotype; genetic sample code: conx5021; Windsor Tableland ) and OM523368 (specimen: QM J92239 ; paratype; genetic sample code: conx5163; Carbine Tableland ) .

Etymology. Nebula sp. nov. = ‘cloud’ (a Latin noun); name reflects the elevated, cloudy habitat.

Distribution. Restricted to upland areas of the Wet Tropics, north-east Queensland ( Fig. 3 ). Known from the Ravenshoe–Herberton area, Lamb Range, Walsh’s Pyramid, Hann Tableland, Carbine Tableland and Windsor Tableland ( Fig. 5 ).

Natural history. Amalosia nebula sp. nov. occurs in rocky areas in upland sclerophyll forests. The lowest elevation record is 750 m above sea level but all other sites are above 800 m elevation (up to approximately 1200 m). Generally found around granite outcrops on ridges and mountaintops (e.g., Fig. 20 ). Found under exfoliating granite in the day and on rock surfaces and tree trunks at night. Nocturnal, probably feeding primarily on invertebrates. Very patchy, occurring at high density in some areas but apparently absent from similar-looking habitat nearby. Amalosia nebula sp. nov. and A. queenslandia sp. nov. co-occur on some of the same mountains and ranges along the western edge of the Wet Tropics ( Fig. 5 ) but Amalosia nebula sp. nov. occurs at higher elevations.

Figures

FIGURE 3. Map of occurrence records of Amalosia species in Queensland and north-east New South Wales. For each species, individuals included in the ND4 sequencing (Fig. 2) are shown as triangles whereas specimen and sighting records are shown as circles. Records of A. robusta are not shown because the copious records obscure presentation of the focal species.

FIGURE 5. Map of occurrence records of Amalosia species in north-east Queensland. For each species, individuals included in the ND4 sequencing (Fig. 2) are shown as triangles whereas specimen and sighting records are shown as circles.

FIGURE 17. Holotype of A. nebula sp. nov. (QM J91178); Windsor Tableland. Photo: Conrad Hoskin.

FIGURE 18. Amalosia nebula sp. nov. in life: (A) Carbine Tableland; (B) Lamb Range; (C) Carbine Tableland; (D) Lamb Range. Photos: (A, B, C) Conrad Hoskin; (D) Stephen Zozaya.

FIGURE 19. Adult A. nebula sp. nov. QM J88684 (Hann Tableland) compared with adult A. queenslandia sp. nov. QM J97599 (Mt Spurgeon). Note the more robust form of A. nebula sp. nov. Photo: Conrad Hoskin.

FIGURE 20. Habitat of A. nebula sp. nov. on Carbine Tableland. Photo: Conrad Hoskin.