Gehyra moritzi, Hutchinson & Sistrom & Donnellan & Hutchinson, 2014

Hutchinson, Mark N., Sistrom, Mark J., Donnellan, Stephen C. & Hutchinson, Rhonda G., 2014, Taxonomic revision of the Australian arid zone lizards Gehyra variegata and G. montium (Squamata, Gekkonidae) with description of three new species, Zootaxa 3814 (2), pp. 221-241 : 235-236

Gehyra moritzi sp. nov

Figs 3 , 9 .

Gehyra 2n=44 " nana-montium " Moritz, 1986: p. 48.

Holotype: SAMA R 65941 K, adult male from Corroboree Rock, East MacDonnell Ranges , Northern Territory (23° 44’ 23.0ˮ S, 133° 57' 02.5" E), collected by M. Hutchinson, P. Oliver, G. Armstrong and S. South on 9 January 2011 ( Fig 9A–B ).

Paratypes (n=17; all genotyped as ‘ Clade 1’): MAGNT: R14356, R 15356, 6 km SSW Claraville HS, NT (23° 25’S, 134° 44’E) , R 18310, Palm Valley Gas Well, Finke Gorge NP, NT (24° 01’S, 132° 37’E) , R 20664, Finke Gorge , NT (24° 08’S, 132° 49’E) . SAMA: R 65935 K –36, Rainbow Valley , NT , R65896–900 , R 65937 K –38, Emily Gap , NT (23° 44’S, 133° 57’E) , R 65895, Corroboree Rock , NT (23° 44’ 23ˮ S, 133° 57’ 03ˮ E, R65881, R65945 K – 46, 20 km S of Barrow Creek, NT (21° 38’S, 133° 44’E).

Diagnosis. Distinguished from other Australian Gehyra by a combination of either 7 or 8 divided scansors under the expanded portion of the fourth toe, small to moderate size, generally two pairs of enlarged chin shields, second or third infralabial notched, dorsal colour pattern combining pinkish grey to rufous colouring (in life) patterned entirely by black and whitish spots, and a karyotype of 2n=44 ( Moritz 1986). Distinguished from most central Australian species ( G. versicolor , G. purpurascens and G. montium ) by its strongly white-spotted pattern with dark markings also forming discrete spots rather than wavy lines or continuous networks. Distinguished from G.minuta and G. pulingka sp. nov. by having black spots rather than short black wavy lines, normally two rather than three pairs of chin shields ( G. pulingka sp. nov.), and higher numbers of labial scales ( G. minuta ).

This diagnosis applies to populations of Gehyra genetically assignable to “Clade 1” of Sistrom et al. (2013).

Description. Adult snout-vent length 36–49 mm (mean = 42.0 mm, n = 19). Length of original tail 38–51 mm (mean = 106% SVL, n = 5).

Nostril bordered by rostral, first supralabial, supranasal and two subequal postnasals. Either a single internasal scale separates the supranasals above the rostral (n= 9) or supranasals in median contact (n= 9). Supralabials 8–10 (mode 9). Infralabials 7–9 (mode 8). Two, less frequently (6/19) three, pairs of chin shields, anterior pair in contact with only the first infralabial. Chin shields separated from the fourth, or third, and succeeding infralabials by the interpolation of a series of enlarged scales (parinfralabials) that margin the ventral edge of the infralabials. Third, less frequently (7/19) second, infralabial notched where this parinfralabial scale row starts. Scansors under pad of fourth toe divided, 7–8 (mode 8). Precloacal pores in males 11–16 (mean = 14.4, n = 11).

The karyotype is 2n=44, regarded as the plesiomorphic karyotype for the Gehyra variegata species group by King (1979) and Moritz (1986), but see Sistrom et al. (2013) for cautionary remarks on this assumption.

In life, dorsally light pinkish grey to reddish brown, the entire dorsal surface patterned by spots. Dark spots are larger and more irregular, pale spots tend to be more precisely circular in shape.

Distribution. Rocky mountain ranges of the south-central Northern Territory centred on the MacDonnell Ranges and south to the James Range, west to the Kings Canyon area and north to the Devils Marbles.

Comments. The above description refers to specimens from the central and southern parts of the species' range. The northernmost sample (SAMA R65875-80, 65943-44), from rocky hills south of the Devils Marbles, is distinctly different in morphology but is not distinguishable by either DNA sequence data or karyotype (SAMA R65943: 2n = 44). This series of eight specimens is consistently smaller (largest specimens only 40 mm SVL), males have fewer precloacal pores (range 8–11) and the spotted colour pattern consists of relatively very small spots, each covering only a few dorsal scales. All have seven enlarged scansors rather than the eight usual for the other populations. The small size, spotted pattern and rock dwelling habits of these animals are reminiscent of G. minuta which occurs close by, but that species has a dorsal pattern with larger pale spots and irregular black flecks rather than spots, lower infralabial counts and frequent contact between the postmental and second infralabial. For the present we refer this sample to G. moritzi but exclude it from the paratype series. Further genetic studies of gecko populations along the Northern Territory portion of the Stuart Highway would be useful to clarify the genetic relationships among G. moritzi populations and the pattern of occurrence of the rock dwelling Gehyra of this region.

The prominently spotted colour pattern of G. moritzi is very similar to that of some Western Australia rockdwelling populations of Gehyra . They are quite genetically distinct (‘punctata clade’ of Sistrom et al. 2013), but the species delineation modeling indicates that they are likely sister taxa. Current chromosomal data ( King 1979, Moritz 1986) suggests a further distinction (2n=44 for G. moritzi , 2n=42a for G. ‘punctata’), but the precise relationships will require further work on Western Australian populations where multiple species are likely present in the Pilbara and adjacent areas. The strong similarity in colour pattern suggests selection for camouflage against rocks, but given their relationships this could be due to common ancestry rather than convergence.

Etymology. The specific name recognises the contribution of Dr Craig Moritz (Australian National University, Canberra, and University of California, Berkeley) in revealing the high level of karyotypic and morphological diversity among central Australian populations of Gehyra .

Figures

FIGURE 3. Distribution of the species of the Gehyra montium - variegata complex, based on populations identified from DNA sequences. Inset shows the detailed distributions of species in the Central Ranges area.

FIGURE 9. Gehyra moritzi sp. nov. A and B. Holotype, SAMA R65941, adult male from Corroboree Rock, Northern Territory, showing a strongly contrasting variant of the colour pattern, shown as preserved and in life. C. Adult female paratype, SAMA R65937, from Emily Gap, Northern Territory, showing a weakly contrasting variant of the colour pattern. D. Adult male, SAMA R65943, from 2 km S of Devils Marbles, Northern Territory, with a pattern of light and dark markings that are smaller relative to the pattern in specimens from the MacDonnell Ranges as exemplified by specimens A and B.