Diplodactylus calcicolus, Hutchinson, Mark N., Doughty, Paul & Oliver, Paul M., 2009

Hutchinson, Mark N., Doughty, Paul & Oliver, Paul M., 2009, Taxonomic revision of the stone geckos (Squamata: Diplodactylidae: Diplodactylus) of southern Australia, Zootaxa 2167, pp. 25-46 : 37-39

Diplodactylus calcicolus sp. nov.

South Coast Gecko

Figs. 10, 11 , 14 E

Diplodactylus 'southern', Oliver et al., 2007a

Holotype. SAMA R25343, adult male, from Hambidge Conservation Park, Eyre Peninsula, SA (33º 26' 40" S, 136º 02' 30" E), collected by the Mammal Club of the SA Field Naturalists’ Society on 23 April 1984 ( Fig. 8).

Paratypes. South Australia ( SAMA specimens): R24763 (M) Lighthouse near Stenhouse Bay (35º17' S, 136º 57' E); R25382 (M) Ifould Campsite No. 2, 62 Km N Colona H/S (30º 56' S, 132º 05' E); R26257 (F) 10 km NE Border Village (31º 36' 50" S, 129º 06' 20" E); R26322 (F) 48 km SE Koonalda Stn (31º 30' 40" S, 130º 21' 30" E); R26495 (F) 11 km NE Border Village (31º 35' 30" S, 129º 07' 20" E); R26496 (M), R26497 (M) 21 km NE Border Village (31º 30' 00" S, 129º 08' 50" E); R36643 (F) Venus Bay (33º 14' S, 134º 40' E); R39517 (M) 5 km S of Monarto South (35º 10' 34" S, 139º 07' 24" E); R44119 (F) Mt Younghusband, St Peter Island (32º 15' S, 133º 37' E); R52488 (F) 28.3 km SSE Port Lincoln (34º 58' 23" S, 135º 57' 08" E).

Western Australia ( WAM specimens): R24602 (F) Eucla (31º 43' S, 128º 54' E); R39921 (M) 2 miles W Greenshield Soak (33º 30' S, 118º 49' E); R56866 (F) Eyre (32º 15' S, 126º 18' E); R91602 (M) 16 km E Toolinna Rockhole (32º 40' S, 125º 07' E); R91627, R91628 and R91630 (all M) 53km WNW Toolinna Rockhole (32º 40' S, 125º 07' E); R93273 (F) and R93275 (F) 32 km NW Clyde Hill (33º 12' S, 122º 43' E); R114154 (F) 4 km N Ravensthorpe (33º 32' S, 120º 03' E); R116051 (F) 3.5 E Calyerup Rocks (33º 53' 26" S, 119º 07' 32" E); R133572 (F) Saint Ronans Nature Reserve (31º 52' 30" S, 116º 36' 10" E); R 140932 (M) and R 140941 (M) 27.5 km SSE Peak Eleanora (33º 10' S, 121º 16' E); R143815 (M) Lake Magenta Nature Reserve (33º 29' 41" S, 119º 02' 53" E); R144224 (M) Bandalup Hill (33º 39' 58"S, 120º 23' 55"E); R149069 (F) Scaddan area (33º 23' 10"S, 121º 34' 58"E); R 151209 (M) Salmon Gums area (32º 48' 36" S, 121º 23' 24" E); R154175 (M) near Kundip (33º 41' 16" S, 120º 11' 52" E); R156209 (F) Kundip (33º 41' 07" S, 120º 11' 50" E); R156943 (M) and R156947 (M) Forrestania area (32º 24' S, 119º 41' E).

Diagnosis. A moderate-sized, longer tailed member of the D. vittatus complex, typically with a highly broken and spotted pattern, but showing considerable within-population variation. Flanks marked with spots of various sizes, and background colour of dorsum usually variegated by a mixture of lighter and darker scales.

Description ( Figs 10, 11 , 14 E). SVL 31.0–58.0 mm (mean 48.9, n=34); tailL 24.5–38.0 mm, mean 32.4, (56.6–72.3% SVL, mean 64.5) (n=18). Supralabials 10–13 (mean 11.5, n=17), first and second supralabial generally subequal or the second slightly higher than the first. Infralabials 8–13 (mean 10.4, n=17). Apex of rostral scale with median division descending to about the mid-height of the scale. Supranasals usually in contact; a single internarial present in 5 of 34 examined. 2–5 postnasals (mean 3.1, n=34).

The most variable in colour and pattern of the group. Dorsal colour pale to very dark brown, grey, or greybrown. Beige to pale grey vertebral stripe most often broken into a disconnected series of irregularly-shaped dorsal blotches, but within population variation can include individuals with a more continuous chain of blotches, or a continuous dorsal stripe with deeply to moderately scalloped margins. Vertebral stripe usually bifurcates on the nape with well-defined lateral margins but irregularly defined inner margins, so that the crown of the head tends to be paler laterally but with a darker, weakly defined central patch of background colour. Blackish paravertebral margins of vertebral stripe variable in contrast, but even if prominent, often discontinuous due to random interruptions by lighter scales. Upper lateral zone sometimes patterned with irregularly distributed circular spots; some specimens with very large spots, similar in size to the vertebral series of blotches. Apart from such spots, the upper lateral surfaces have a ‘messy’ texturing of lighter and darker scales overlying the medium-toned background colour. Ventral surface white to greyish white.

Karyotype. 2n=38 ( King 1977).

Distribution. Distributed along the dry temperate to arid southern coast and hinterland of Australia, from near Perth, WA, south to Albany (absent from southwest corner) and along the Great Australian Bight to the Eyre Peninsula, with outliers on the southern York Peninsula and the mouth of the Murray River ( Figs 1 , 15 , 16 ).

Etymology. The specific name has been constructed from Latin roots ' calci ' (lime) and ' cola' (inhabitant), referring to the dominant limestone geology of the coast and hinterland of the Great Australian Bight, the central area of the species’ distribution.

Similar Species. This is the most variable species within the complex, and it overlaps geographically with all other taxa treated here except D. g. rex . Within most populations of D. calcicolus a minority of specimens have a continuous vertebral stripe combined with weakly marked flanks. Such individuals are difficult to distinguish from sympatric individuals of D. furcosus , D. g. granariensis , or D. vittatus . The stripe is more irregular than in either of the other species, the flanks have intermixed darker and lighter scales rather than being uniformly coloured and the occipital markings are usually more poorly defined ( Fig. 9 ). The longer tail of D. calcicolus sp. nov. further distinguishes it from D. vittatus in the small overlap zone on the lower Murray River. In the southwest of Western Australia, the diffuse spotted markings of D. polyophthalmus are unlike the more solidly delineated and irrregular spots of D. calcicolus . At present, distinguishing some far western D. calcicolus sp. nov. from geographically proximate individuals of D. ornatus can be difficult. More detailed genetic comparisons among Perth area Diplodactylus populations, focusing on the distinctions between D. calcicolus sp. nov. and D. ornatus , will be necessary before the unambiguous genetic distinction can be matched by equally clear morphological characters..

Remarks. This species mostly occurs in cool dry habitats, typically on limestone or calcareous coastal sands. Oliver et al. (2007a) noted that this species comprises three genetic lineages that do not correspond to any obvious patterns of variation in the characters discussed above.

Figures

FIGURE 1. Map of southern Australia showing the distribution of the members of the Diplodactylus vittatus species complex described or re-described in the present study. Insets shows details of species distributions in overlap areas in Western Australia and South Australia (See Figs 15 and 16). Diplodactylus vittatus, square; D. furcosus, black cross, D. g. granariensis, circle; D. g. rex, circle with central dot, D. calcicolus sp. nov., grey cross, D. wiru sp. nov., triangle.

FIGURE 9. Variation in colour pattern in Diplodactylus granariensis rex

FIGURE 11. Variation in colour pattern in Diplodactylus calcicolus sp. nov. From left to right: western specimens (WAM R 140935, WAM R 156947, WAM R 156943), Nullarbor specimens (SAM R 59582, SAM R 59524), and eastern specimens (SAM R 40554, SAM R 58537, SAM R 36644).

FIGURE 14. Species of the Diplodactylus vittatus complex in life. A, D. vittatus, Warrumbungle Range, NSW, (M. Hutchinson); B, D. furcosus, Whyalla, South Australia (T. Peters, SA Museum); C, D. g. granariensis, Newman Rock, WA (B. Maryan); D, D. g. rex, Wildara Pinnacle, WA (B. Maryan); E, D. calcicolus sp. nov., vicinity of the WA-SA border (G. Harold); F, D. wiru sp. nov. Lake Ifould, SA (P. Oliver).

FIGURE 15. Detail of distribution of D. vittatus complex in Western Australia. Note significant range overlap of D. granariensis and D. calcicolus sp. nov. in the southwest. Symbols as in Fig. 1.

FIGURE 16. Detail of distribution of D. vittatus complex in South Australia. Note significant range overlap of D. furcosus and D. calcicolus sp. nov. on Eyre Peninsula, and the two regions (arrowed) where three species are sympatric. Symbols as in Fig. 1.