Diplodactylus galeatus Kluge, 1973

McDonald, Peter J., Fenner, Aaron L., Torkkola, Janne & Oliver, Paul M., 2024, Vicars in the desert: Substrate specialisation and paleo-erosion underpin cryptic speciation in an Australian arid-zone lizard lineage (Diplodactylidae: Diplodactylus), Vertebrate Zoology 74, pp. 577-594 : 577-594

Diplodactylus galeatus Kluge, 1973

Figures 5 A, B

Southern mesa gecko

Holotype.

SAMA R 973 , a male collected on the Stuart Range , South Australia (29.92 ° S, 134.67 ° E) by H. Greenfield; designated by Kluge (1973).

Diagnosis from other species in the D. galeatus complex.

Diplodactylus galeatus may be distinguished from D. tjoritjarinya sp. nov. (see below) by the larger ear opening (usually> 6 % of head width or ≥ 0.6 mm in diameter in adults versus usually <6 % of head width or ≤ 0.5 mm in diameter in D. tjoritjarinya sp. nov.), the presence of dorsal blotches descending ≥ 1 / 4 distance down torso when animal is viewed in lateral profile (versus typically descending ~ 1 / 8 down torso in D. tjoritjarinya sp. nov.), the presence of large white spots (> 3 scales in diameter) in the dorso-lateral region often arranged as mid-lateral row of ‘ portholes’ (versus smaller spots only), and by the dark red background colouration (versus pinkish red or red-brown). Diplodactylus galeatus may be distinguished from D. fyfei sp. nov. by the smaller relative rostral scale height (usually ≤ 2.2 % of SVL versus usually> 2.2 % SVL in D. fyfei sp. nov.). Diplodactylus galeatus further differs from the very similar D. fyfei sp. nov. in at least 20 putatively fixed differences in the mitochondrial ND 2 locus (see Table 2 ).

Description.

A medium-sized (to 56 mm) Diplodactylus with a robust build; head moderately wide (HeadW / HeadL – mean = 0.65, range = 0.56–0.74) and deep (HeadD / HeadL – mean = 0.44, range = 0.38–0.54); eyes large (OrbL – mean = 3.5 mm, range = 2.8–4.1); external ear opening relatively large (mean headW / ear = 0.08, range = 0.04–0.11). Supralabials much larger than bordering loreals, wider than high and decreasing in height posteriorly, first supralabial slightly taller or equal in height to second; infralabials 10–12; nostril surrounded by rostral scale, supranasals 2 and postnasals 3–5; relatively low rostral scale (Ros / SVL – mean = 0.021, range = 0.017 –0.025), rostral crease usually present and descending one quarter to halfway from top of scale; mental scale lanceolate in shape and always longer than wide.

Scales on dorsum enlarged, up to twice diameter of those on lateral and ventral surfaces; dorsal head scales larger relative to neighbouring sides of head; scales on throat small and granular. Subdigital lamellae in single row of enlarged rounded scales; apical pad pair prominent and enlarged, much wider than proximal width of digit. Males have 3–7 cloacal spurs (median 5); females have rounded scales where the male spurs occur. Original tail short (mean Tail % SVL – mean = 0.51, range = 0.45–0.56) and thick, cylindrical, with regular annuli of slightly enlarged tubercles on dorsal and upper lateral surfaces.

Top of head pale and yellowish-brown bordered posteriorly by a rounded dark line, dorsum dark red brown with four to five dark-edged pale blotches (rarely merged to form a continuous vertebral stripe; 14 % of individuals) that descend ≥ 1 / 4 distance down torso when animal is viewed in lateral profile, lateral region of torso with numerous white dots (including some> 3 scales wide) and frequently arranged in mid-lateral row, limbs usually with scattered white spots, and ventral surface white.

Particulars of holotype.

SAMA R 973 adult male (all measurements in millimetres): SVL = 52.7, TrunkL = 23.4, TailL = 27.0, TArmL = 20.3, TlegL = 25.0, HeadL = 14.8, HeadW = 10.4, RosCre = 0.0, SupNas = 2, SupLab = 9, InfLab = 11, Cspurs = 6, 4 Flam = 7; 4 Tlam = 8.

Etymology.

Derived from the Latin word galea meaning covered with a helmet in reference to the dark occipital cap.

Distribution and ecological notes.

Endemic to South Australia and restricted to the western Stony Plains IBRA region (Thackway and Creswell 1995). Recorded from Prominent Hill in the south, north to approximately 15 km north of Iwantja and east to near Old Peake Telegraph Station.

Occurs on and around dissected tablelands or ‘ breakaway’ hills with sparse tussock grass and lower shrub layers and a very sparse Acacia shrub overstory. Observed to be abundant in some areas of its range, with large numbers of specimens observed in a relatively short period of spotlighting in the Breakaways near Coober Pedy (P. Oliver pers. obs.). Recorded in syntopy with Gehyra versicolor and Heteronotia binoei .

Suggested IUCN Red List status.

Diplodactylus galeatus has a moderately large range (EOO 23,012 km 2) spanning areas that are sparsely inhabited, not subject to widespread habitat destruction or disturbance and including several protected areas (6.96 % of the Stony Plains bioregion). Based on these data we suggest that it be considered Least Concern.

Figures

Figure 5. Colour-pattern variation in the Diplodactylus galeatus species complex: A, B Diplodactylus galeatus from Coober Pedy, SA (P. McDonald, A. Fenner), C, D Diplodactylus fyfei sp. nov. from foothills of Mt Beddome on New Crown Station, NT (P. McDonald, A. Fenner); E, F D. tjoritjarinya sp. nov. from Tjoritja National Park, Northern Territory (P. McDonald).