Diplodactylus ameyi, Couper, Patrick J. & Oliver, Paul M., 2016

Couper, Patrick J. & Oliver, Paul M., 2016, A new species of gecko from arid inland regions of eastern Australia (Diplodactylus; Diplodactylidae), Zootaxa 4093 (4), pp. 525-538 : 526-535

publication ID	https://doi.org/ 10.11646/zootaxa.4093.4.4
publication LSID	lsid:zoobank.org:pub:E82F1550-79EA-4E83-A65B-0F5D2E8C011D
DOI	https://doi.org/10.5281/zenodo.5621900
persistent identifier	https://treatment.plazi.org/id/40094134-FFB9-FFD6-FF3A-3AE3B9DCFE95
treatment provided by	Plazi
scientific name	Diplodactylus ameyi
status	sp. nov.

Treatment

Diplodactylus ameyi sp. nov.

Eastern Deserts Fat-tailed Gecko Figs: 2, 3, 4A, 5A, 6, 7 (top row)

[ Diplodactylus ] ‘ conspicillatus ’ F (Oliver et al. 2009)

Holotype. QM J90778 View Materials ( Fig. 2 View FIGURE 2 ), 3.4km NNE Noonbah homestead (24°04'51"S, 143°11’54”E) Queensland, Australia, frozen tissue sample at South Australian Museum ABTC113844, collected by Mark Hutchinson.

Paratypes. Queensland. SAMA R63336, Winton, (22°27'S, 142°57'E); QM J92287 View Materials , Winton (22°28'42"S, 142°53'31"E); AMS R 110564, Camp 14km NE Scott’s Tank, Diamantina Lakes , NW of Windorah (23°45'S, 141°40'E); AMS R 110529, Scott’s Tank, Diamantina Lakes , NW of Windorah (23°58'S, 141°32'E); QM J83467 View Materials , Noonbah Station (24°07'S, 143°11'E); QM J90774 View Materials , Noonbah homestead, 3.4km NNE (24°04'51"S, 143° 11'54"E); QM J90170 View Materials , Valetta Stn (24°15'21"S, 143°05'57"E); QM J59978 View Materials Jundah. ‘Noonbah Stn’ Rd to 'Waterloo Stn' in Bore Paddock (24°07'40"S, 143°11'30"E); QM J56888 View Materials , Waterloo site 1 (24°16' S, 143°13'E); AMS R 143856, Stonehenge area, within 10km N to S of Stonehenge (24°22'S, 143°19'E); QM J89191 View Materials , Tyrone, approx 70km NW of Charleville - 3km S of old north Tyrone homestead (25°58'55"S, 145°44'17"E); QM J35697 View Materials , Ambathala, 1km S Ra Tank (26°01' 30"S, 145°04'30"E); QM J79909 View Materials , Mariala (26°05'S, 145°04'E); QM J74874 View Materials , Mariala Nature Ref. (26°05'30"S, 145°04'15"E). New South Wales. AMS R158426, Sturt NP, Silver City Hwy, Wittabrinna Ck. Crossing (29°22'38"S, 142°02'08" E); AMS R132996, AMS R132997, Wanaaring, 4km W of Wanaaring at Turnoff to Wilcannia (29°42'S, 144°07'E); AMS R141988, Wanaaring (29°42'S, 144°09'E); AMS R165698, Nocoleche Nature Reserve, 11km W of Wanaaring - Wilcannia Rd (29°52'08"S, 144°00'34"E); AMS R165659, AMS R165697, AMS R166837, Nocoleche Nature Reserve, 11km West of Wanaaring - Wilcannia Road (29°52'08"S, 144°00'34" E); AMS R162733, AMS R165673, Lake Peery National Park (30°43'28"S, 143°29'15"E).

Species-group diagnosis. A member of the Diplodactylus conspicillatus group as defined by the following combination of characters: most supralabials small and granular, at most only one enlarged anterior (first) supralabial; terminal lamellae on fingers at most only slightly wider than digit; prominent enlarged subdigital lamellae absent; tail short, as wide or wider than body, depressed with heterogeneous scalation, and bearing large plate-like scales and/or conical tubercules arranged in transverse rows; and dorsal colouration extremely variable, but lacking large well defined bands or blotches.

Specific diagnosis. A large member of the D. conspicillatus group (max SVL = ~ 60 mm) in which the first supralabial is small and does not contact the ventral edge of nasal scale ( Fig. 3 View FIGURE 3 ). Snout broad and ‘U’-shaped snout (dorsal view, Fig. 4 View FIGURE 4 A), convex along its dorsal edge and lacking a well-defined canthus rostralis ( Fig. 5 View FIGURE 5 A). The canthal stripe is absent or poorly defined ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 , 4 View FIGURE 4 A, 5A, 6 & 7 - top row).

Description. SVL mm 46.0–60.2 (n = 22, mean = 53.2, SD = 4.3). Proportions as % SVL: AG 42.2–55.9 (n = 22, mean = 48.9, SD = 3.4); T 33.2–44.7 (n = 15, mean = 37.8, SD = 3.0). Head: broad and deep but not strongly differentiated from neck; snout longer than diameter of eye, broad and blunt (U-shaped when viewed from above; Fig. 4 View FIGURE 4 A), with a conspicuous bulbous swelling anterior to the eyes (resulting in a poorly defined canthus rostralis), and gently convex along dorsal edge in lateral profile ( Fig 5 View FIGURE 5 A). HW 76.9–92.3% HL (n = 22, mean = 83.8, SD = 4.5); HD 44.8–57.0% HL (n = 22, mean = 48.9, SD = 3.2); S 42.5–48.6% HL (n = 22, mean = 45.4, SD = 1.15); EE 24.0–32.1% HL (n = 22, mean = 28.2, SD = 2.4); covered in small granular scales; rostral shield large and lacking a medial groove, hexagonal with 8–13 scales contacting posterior edge (n = 22, mean = 10.5, SD = 1.3); mental shield hemispherical; 10–15 scales contacting posterior edge (n = 22, mean = 12.1, SD = 1.3); supralabial scales 11–18 (n = 22, mean = 15.0, SD = 2.0), the first not enlarged and subequal with the rest of the supralabial row which are not differentiated from the adjacent loreal scales ( Fig. 3 View FIGURE 3 ); infralabial scales 12–19 (n = 22, mean = 15.1, SD = 1.9), small and barely differentiated from adjacent chin scales; eye large, pupil vertical with crenulated margin; ear small, round to horizontally elliptic. Neck: broad with small granular scales on dorsal surface that are only slightly larger than the adjacent scales on the lateral surfaces. Trunk: moderate and somewhat stout; scales of dorsum plate-like and markedly larger than the granules on flanks; scales granular on ventral surface but increase in size on pectoral region; precloacal pores absent; a small cluster of postcloacal tubercles present in both sexes but larger and more prominent in males. Limbs: moderate; forelimb 28.3–37.1 % SVL (n = 22, mean = 32.5, SD = 2.5); hindlimb 31.1–40.8 % SVL (n = 22, mean = 35.5, SD = 2.6); digits moderate with no or only slight distal expansion; subdigital scales granular with a small pair of apical lamellae; 9–13 scales beneath fourth finger (n = 22, mean = 11, SD = 1.0); 9– 14 scales beneath fourth toe (n = 22, mean = 11.7, SD = 1.19). Original tail: short 33– 45% SVL, width 48.0–78.8% of tail length (n = 15, mean = 61.1, SD = 7.9); spade-like and bluntly pointed (lacking an acute attenuated tip); dorsal scales each with a short blunt to sharp medial tubercle, arranged in clear transverse series which are usually more or less uniform in size (but may include rows of smaller scales); 23–32 (n = 15, mean = 26.2, SD = 2.1) medial scale rows on tail in longitudinal series from fracture plane (1st autotomy septum) to tip; 13–18 (n = 15, mean = 14.4, SD = 1.3) rows of scales across original tail (large row at maximum width); ventral scales considerably smaller than dorsal scales, flat and not arranged in regular rows. Regrown tail: rounded distally, scales not arranged in clear transverse rows.

Pattern (in spirit, Fig. 2 View FIGURE 2 , 7 View FIGURE 7 - top row). Variable. Most specimens tan to medium-dark brown with heavy, pale spotting on the flanks. Dorsum with an overlay of fine dark reticulations and pale spotting (usually smaller than those on flanks). The vertebral zone has reduced pigmentation and is marked by a series of pale blotches (~5–6 between the pectoral and pelvic girdles) which in some specimens are narrowly broken and slightly misaligned across the vertebral line. Head, as for dorsal ground colour with scattered dark flecks or blotches. Canthal stripe absent or weak without sharply defined edges and not contrasting strongly with other facial markings. Limbs with fine reticulations, inner digit of forelimb with reduced pigmentation. Ventral surfaces off-white, immaculate. Original tail as for trunk but usually with broader, dark markings that form a coarse reticulated pattern.

Measurements and scale counts of holotype (in mm). QM J90778 View Materials ♀ ( Fig. 2 View FIGURE 2 ), SVL = 60.2, MBW = 14.1, MBD = 7.6, AG = 28.3, L1 = 17.3, L2 = 20.0, HL = 11.0, HD = 5.7, HW = 9.1, S = 5.1, EE = 3.3, TL = 23.3, TW = 14.4, scales contacting posterior edge of rostral = 11, scales contacting posterior edge of mental = 10, lamellae beneath 4th finger = 10, scales beneath 4th toe (basal junction to tip) = 12, medial scale rows on tail from fracture plane (1st autotomy septum) to tip = 26, rows of scales across original tail = 14, supralabials = 16, infralabials = 15.

Etymology. Named for Dr Andrew Amey for his contributions to documenting Australia’s herpetofauna and promoting access to the Queensland Museum’s reptile and amphibian collections.

Comparisons. Diplodactylus ameyi sp. nov. can be distinguished from Diplodactylus barraganae Couper, Oliver & Pepper (in Oliver et. al., 2014), Diplodactylus bilybara Couper, Pepper & Oliver (in Oliver et. al., 2014), D. conspicillatus Lucas & Frost (1897) , Diplodactylus custos Couper, Oliver & Pepper (in Oliver et. al., 2014), Diplodactylus hillii Longman (1915) and Diplodactylus laevis Sternfield (1924) in possessing a small first supralabial that is not differentiated from the rest of the supralabial row (vs. enlarged and contacting ventral edge of nasal scale) and in lacking a well-defined canthal stripe (vs. canthal stripe well-defined). It further differs from D. bilybara , D. custos and D. laevis in lacking an acute attenuated extension at the tip of the original tail.

Diplodactylus ameyi sp. nov. differs from all known populations of D. platyurus (which may be composite, containing at least two additional candidate taxa - lineages G & H in Oliver et al., 2014) in having a broad Ushaped snout (dorsal view) which is convex along its dorsal edge and lacks a well-defined canthus rostralis ( Figs 2 View FIGURE 2 , 4 View FIGURE 4 A, 5A, 6, 7 top row). All` D. platyurus’ populations have finely tapered (V-shaped) snouts with a prominent canthus rostralis, suggesting significant differences in the underlying skull morphology ( Figs 1 View FIGURE 1 , 4 View FIGURE 4 B, 5B & C, 7 middle and bottom rows). Diplodactylus ameyi sp. nov. tends to have more scales contacting the posterior edge of the rostral shield (8–13, 10.5 ± 1.3 vs. 5–10, 7.9 ± 1.4 in `D. platyurus’). Diplodactylus ameyi sp. nov. also obtains a greater SVL (max SVL = ~ 60 mm vs. <56 mm in` D. platyurus’) ( Figure 7 View FIGURE 7 ).

Distribution and vegetation associations ( Figs. 8 View FIGURE 8 , 9 View FIGURE 9 ). Diplodactylus ameyi sp. nov. occurs widely across the eastern edge of the Eromanga Basin, from Winton in the north to the north-western edge of New South Wales. The distribution of museum specimens suggests a geographic hiatus between northern and southern samples ( Fig. 8 View FIGURE 8 ) but further fieldwork is required to establish if this is simply an artefact of sampling.

This species occurs widely through arid woodland habitats on a range of sand and clay-based substrates throughout its range (typical habitat at one collection site is illustrated in Fig. 9 View FIGURE 9 ). The following habitat notes are associated with specimens in the Queensland Museum collection: QM J83467 View Materials ‘Red sandy soils Acacia cambagei associations’; QM J59978 View Materials ‘Open flat, few low bushes. Red sandy soils’ and QM J74874 View Materials , QM J89191 View Materials and QM J90170 View Materials were found in association with Mulga woodlands ( Acacia aneura ).

Dietary note. The stomach of QM J90778 View Materials (the holotype, collected 1 May 2010) was examined to determine prey species. Its contents comprised ~ 85% worker termites and 15% ants belonging to the genus Iridomyrmex ( Formicidae : Dolichoderinae ).