Strophurus assimilis (STORR, 1988)
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Higher Taxa | Diplodactylidae, Gekkota, Sauria, Squamata (lizards: geckos) |
Subspecies | |
Common Names | E: Goldfields Spiny-tailed Gecko |
Synonym | Diplodactylus ciliaris ciliaris X D. c. intermedius — KLUGE 1967 Diplodactylus assimilis STORR 1988 Strophurus assimilis — WELLS & WELLINGTON 1989 Strophurus assimilis — GREER 1989 Strophurus assimilis — KLUGE 1993 Diplodactylus assimilis — COGGER 2000: 214 Strophurus assimilis — RÖSLER 2000: 115 Strophurus assimilis — WILSON & SWAN 2010 |
Distribution | Australia (arid and semiarid interior of S Western Australia) Type locality: 15 km NE, Bungalbin Hill, WA, in 30 18'S, 119°44'E. |
Reproduction | oviparous |
Types | Holotype: WAM R72164 |
Diagnosis | Diagnosis: A small member of the complex (total length up to 128 mm long), very like D. intermedius but larger and having a relatively longer tail, fewer internasals (mode 1, v. 3) and dorsal tubercles arranged in two wavy or discontinuous rows (not two continuous parallel rows). Distinguishable from D. wellingtonae, D. ciliaris ciliaris and D. c. aberrans by much shorter spines above eye and on tail. (Storr, 1988) DIAGNOSIS: Strophurus assimilis can be distinguished from other members of the genus by the following combination of characters: a continuous to near continuous (sometimes broken) wavy row of enlarged unicoloured tubercles along the dorsolateral margin of the body (Figures 5, 7A–B); tail with a single row of enlarged unicoloured spines on either side of the tail that progressively increase in size and become more spinose approaching the distal part of the tail (Figures 6A, 7A, 7C); scales in a transverse line across the tail between longitudinal rows of enlarged caudal spines scales mid-tail 2–3 in number at mid-tail, and typically significantly larger than surrounding tail scales; colour of mouth lining deep blue. Of the species likely to be confused with Strophurus assimilis, only Strophurus spinula sp. nov., some populations of Strophurus ciliaris, and Strophurus wellingtonae have a single row of enlarged, unicolored, spines on either side of the tail. Strophurus assimilis can be distinguished from populations of S. wellingtonae and S. ciliaris with unicolored spines on either side of the tail in having the 2–3 vs 7–11 and 4–7 scales, respectively, in a transverse line across the tail between the longitudinal rows of enlarged caudal spines at mid-tail, and in these being larger vs similar in size to the surrounding tail scales. Further, S. assimilis can be distinguished from S. ciliaris in having a blue vs yellow mouth colouration. Strophurus assimilis can be distinguished from S. spinula sp. nov. in having the distal spines of the tail increasing is size compared to those preceding, whereas S. spinula sp. nov. has the distal tail spines decreasing in size. Strophurus assimilis can be further distinguished from S. spinula sp. nov. in having the enlarged tubercles along the dorsolateral margin of the body present as a more-or-less continuous wavy row of enlarged tubercles down the body row vs straight but discontinuous row. (Sadlier et al. 2023) Measurements: Maximum snout-vent length (SVL) 80.8mm (adults x̄ = 67.0, range 53.7–80.8, n = 22); tail length 49.3–66.3% of SVL (x̄ = 54.9%, n = 17); axilla to groin length 41.9–51.3% SVL (x̄ = 46.4, n = 22); head length 23.9–28.3% SVL (x̄ = 26.2%, n = 22); head width 62.6–78.6% of head length (x̄ = 70.2%, n = 22); hind limb length 36.7–48.8% SVL (x̄ = 41.7%, n = 22). (Sadlier et al. 2023) Scalation: Nostril surrounded by rostral, single supranasal, usually two postnasals (occasionally three), and first labial. Rostral divided by a median groove. Internasals usually one (rarely two). Enlarged ciliary spines 2–7 (mode 5), and moderate in length (2 times that of adjacent scales). Underside of digits of forelimbs with single pair of large apical plates, followed on fourth digit by 3–5 (mode 4) transverse lamellae and proximally by 1–3 (mode 2) pairs of elliptical or circular scales. Underside of digits of hind limbs with pair of large apical plates, followed on fourth digit by 4–5 (mode 4) transverse lamellae and proximally by 1–3 (mode 2) pairs of elliptical or circular scales. Precloacal pores in males 12–17 in total, separated medially by 1–2 (rarely 3) poreless scales. Cloacal spurs 2–3 either side (mode 2). Enlarged dorsal tubercles of the body arranged as a single, parallel row on each side down the paravertebral axis of the body, wavy in alignment and typically continuous over most of its length, but broken anteriorly at and just posterior of the forelimbs in some individuals. Enlarged dorsal spines of original tail in a regular arrangement of 18–20 (x̄ = 18.3 + 0.7, n = 17) rows down either side of the tail. At mid-distance along tail these spines are separated (transversely) by 2–4 scales across the tail, these intervening scales consisting of an enlarged tubercle with or without an additional smaller enlarged scale (also typically larger than the adjacent granular tail scales), and by 5 (rarely 4) intervening scales between the enlarged spines down the tail. (Sadlier et al. 2023) Colour and pattern: Dorsal surface light to mid grey, occasionally darker, and contained within a dorsolateral series of enlarged, tan to dull orange-coloured tubercles that form a wavy edge down either side of the body. Dorsal surface of body relatively uniform but sometimes with irregular dark markings anteriorly concentrated as a wavy dorsolateral edge along the underside of the enlarged tubercles, and extending anteriorly as a wavy margin to the top of the eye. Base colour of the lateral surface of the body usually similar to the dorsal surface. Some individuals darker in tone and with a pattern of elongate and irregular (sometimes diamond-shaped) and variably connected paler blotches on the lateral surface, aligned and variably continuous with a pale temporal streak along the side of the head to the back of the eye. A variably defined pale canthal stripe along the snout, and in some more or less extending along the side of the tail. Individuals with this pattern (Figure 6A) present a two-toned (darker dorsal/lighter lateral) appearance by virtue of the paler lateral markings dominating the surface appearance. The dark dorsal colouration of two-toned individuals extends across the top of the head uniformly or broken into large blotches. Ciliary spines usually grey-brown to tan, occasionally lighter grey or brown to dark brown. Tail similar in colour and pattern to body, with the enlarged tail tubercles similar in colour to those on the body, and in some individuals the enlarged intercaudal scales similarly coloured. The reticulated part of the iris in the image of both live individuals from the Coolgardie and Norseman area in Western Australian (Figure 6) and from Eyre Peninsula in South Australia (Figure 7A) is ringed in dark brown. (Sadlier et al. 2023) Variation: There is variation in the extent of enlarged dorsal tubercles down each side of the paravertebral axis of the body between the insertions of the limbs. In Western Australia, this row is typically continuous and wavy over most of its length (Figure 5) in populations in the north-west (Bungalbin Hill area) and south-west of its range (i.e., Yellowdine and Southern Cross), but can be broken and discontinuous anteriorly at and just posterior of the forelimbs (Figure 6) in some populations in the east of its range in Western Australia (i.e., Coolgardie and Norseman). Those individuals with the enlarged dorsal tubercles broken or reduced in number anteriorly and lacking an original tail can be difficult to distinguish from Strophurus spinula sp. nov. In the Queen Victoria Springs area at the eastern extremity of the species distribution in Western Australia, several specimens (WAM R15213, R58709, R99605, R99606 R100621) had the enlarged dorsal tubercles down each side of the body, wavy in alignment over most its length, in some broken and discontinuous anteriorly, and three had an original tail with the distal spines increasing is size — these could be unequivocally assigned to Strophurus assimilis. Other specimens from the area Queen Victoria Springs (WAM R15214, R48652, R48657, R48658) had the enlarged dorsal tubercles down each side of the body broken and discontinuous anteriorly, and to some extent posteriorly, and one had the row of tubercles broken and discontinuous over much its length down the body — all did not have original tails and could not be unequivocally assigned to S. assimilis and are here listed as incertae sedis. The extent of variation observed at this location in the presence and alignment of the enlarged dorsal tubercles of the body highlights the difficulty in determining the identity of individuals on this character alone where the original tail has been lost. Conversely, most of the specimens and images of individuals from the population in the Eyre Peninsula and adjacent areas in South Australia have the line of enlarged dorsal tubercles between the insertions of the limbs continuous and wavy over most its length (Figure 7A–B), and the enlarged dorsal tubercles of the tail spinose in appearance (Figure 7A and C). Images of live individuals of this population typically have a light to mid ground colour with enlarged dorsal tubercles of the body and tail tan to dull orange. Populations in Western Australia have fewer enlarged ciliary scales (2–5, mode 3) than those on the Eyre Peninsula (4–7, mode 5) and in the eastern Great Victoria Desert region (5–6, mode 5) of South Australia. (Sadlier et al. 2023) |
Comment | Group: Diplodactylus strophurus group. |
Etymology | Latin for similar (to the closely related D. intermedius). |
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