Diplodactylus fyfei, McDonald & Fenner & Torkkola & Oliver, 2024

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 fyfei sp. nov.

Figures 5 C, D, S 2

Fyfe’s mesa gecko

Holotype.

NTM R 39440 , a male collected in the foothills east of Mt Beddome on New Crown Station (25.78252 ° S, 134.35169 ° E) by P. McDonald on 3 rd December 2023.

Paratypes.

NTM R 39439 , female, foothills east Mt Beddome , New Crown Station, NT (25.78252 ° S, 134.35169 ° E) ; NTM R 39441 , female, foothills near Mt Beddome , New Crown Station, NT (25.78252 ° S, 134.35169 ° E) ; SAMA R 25851 , male, Eringa Station , SA (26.28 ° S, 134.72 ° E) ; SAMA R 47003 , female, 10 km WSW of Mosquito Camp Dam , New Crown Station, SA (26.1606 ° S, 134.3997 ° E) .

Referred material.

NTM R 39442 , foothills east of Mt Beddome , New Crown Station, NT (25.78252 ° S, 134.35169 ° E) ; NTM R 39443–4 , foothills of Mt Beddome , New Crown Station, NT (– 25.78122 ° S, 134.36182 ° E) ; SAMA R 25852 , Eringa Station , SA (26.28 ° S, 134.72 ° E) ; SAMA R 47002 , 10 km WSW of Mosquito Camp Dam , New Crown Station, SA (26.1606 ° S, 134.3997 ° E) ; SAMA R 47004 , 10 km WSW of Mosquito Camp Dam , New Crown Station, SA (26.1606 ° S, 134.3997 ° E) .

Diagnosis from other species in the D. galeatus complex.

Diplodactylus fyfei sp. nov. may be distinguished from D. tjoritjarinya sp. nov. (see below) by 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 fyfei sp. nov. may be distinguished from D. galeatus by the larger relative rostral scale height (usually> 2.2 % of SVL versus usually ≤ 2.2 % SVL in D. galeatus ). Diplodactylus fyfei sp. nov. further differs from the very similar D. galeatus in at least 20 putatively fixed differences in the mitochondrial ND 2 locus (see Table 2 ).

Description.

A medium-sized Diplodactylus (to 53 mm) with robust build; head moderately wide (HeadW / HeadL – mean = 0.66, range = 0.58–0.76) and deep (HeadD / HeadL – mean = 0.45, range = 0.38–0.52); eyes large (OrbL – mean = 3.4 mm, range = 2.3–3.8); external ear opening relatively large (mean HeadW / Ear = 0.06, range = 0.05–0.08). Supralabials, 8–10, much larger than bordering loreals, wider than high and decreasing in height posteriorly, first supralabial slighty taller or equal in height to second; infralabials 10–12; nostril surrounded by rostral scale, supranasals 2 and postnasals 3–5; relatively high rostral scale (Ros / SVL – mean = 0.023, range = 0.021 –0.028), 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; 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 5–6 cloacal spurs (median 5); females have rounded scales where the male spurs occur. Original tail short (mean Tail / SVL – mean = 0.52, range = 0.47–0.60) 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 of dark red brown with 4–5 (median = 5) dark-edged pale blotches (rarely merged to form a continuous vertebral stripe; 9 % 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, dorsal colouration and pattern continue onto original tail (with 2–5 blotches), and ventral surface white.

Particulars of the holotype.

An adult male (Fig. S 2). SVL = 46.9, TrunkL = 19.6, TailL = 26.5, TailW = 5.8, ArmL = 8.3, LegL = 9.6, HeadL = 15.1, HeadW = 10., HeadD = 7.7, IO = 7.4, NarEye = 4.5, Internar = 1.6, Ros = 1.1, RosCre = 0.4, MentalL = 1.6, MentalW = 1.2, SupNas = 2, SupLab = 13, InfLab = 12, CSpurs = 5, 4 FLam = 6, 4 TLam = 10, No. SC = 49. Rostral scale height relatively large (2.3 % of SVL). Five pale dorsal blotches present on body and extending up to 1 / 3 down torso when viewed in lateral profile. Large white spots (> 3 scale in diameter) present on dorso-lateral region and arranged as mid-lateral row of ‘ portholes’.

Etymology.

Named for the pioneering herpetologist Greg Fyfe in recognition of his substantial contribution to the knowledge and conservation of central Australia’s reptile fauna.

Distribution and ecology.

Restricted to extreme northern Stony Plains IBRA region ( Thackway and Cresswell 1995) straddling the Northern Territory / South Australia border. Records in the Northern Territory are associated with Beddome Range on New Crown Station. Potentially suitable habitat also occurs further west on Umbeara and Tieyon Stations in NT and SA, respectively.

Recorded nocturnally active on the ground in and around dissected tablelands or mesas on sandstone and shale geologies. Vegetation usually includes a sparse tussock grass and lower shrub layers and a very sparse Acacia shrub overstory. Usually observed perched atop rocks rather than actively foraging and one individual was encountered in a low shrub ( Eremophila freelingii ) (P. McDonald pers. obs.). Recorded in syntopy with Gehyra versicolor , Heteronotia binoei and Underwoodisaurus milii .

Suggested IUCN Red List status.

Diplodactylus fyfei sp. nov. has the smallest distribution of the three taxa in the D. galeatus species complex (EEO = 654 km 2) and has not been recorded from any protected areas. However, it is likely that further sampling in areas of dissected tableland along the NT / SA border to the west will increase its known range. Further, the areas inhabited by Diplodactylus fyfei sp. nov. are sparsely inhabited and have not been subjected to widespread habitat destruction or disturbance. 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).