Lerista hobsoni, Couper, Patrick J., Amey, Andrew P. & Wilmer, Jessica Worthington, 2016

Couper, Patrick J., Amey, Andrew P. & Wilmer, Jessica Worthington, 2016, Cryptic diversity within the narrowly endemic Lerista wilkinsi group of north Queensland — two new species (Reptilia: Scincidae), Zootaxa 4162 (1), pp. 61-91 : 76-79

Lerista hobsoni sp. nov. Amey, Couper and Worthington Wilmer

Hobson’s Fine-lined Slider

( Figs. 6 B, 7–8)

Holotype. QMJ93709, Rubbish Tip Rd, Pentland, CQ (20° 31' 46" S, 145° 24' 13" E), 16 September, 2014.

Paratypes. QMJ40098, male, Battery Station , 90 km NNW Charters Towers, NEQ (19° 29' 54" S, 145° 39' 30" E), 3 December, 1981 ; QMJ40099, Battery Station , 90 km NNW Charters Towers, NEQ (19° 29' 54" S, 145° 39' 30" E), 3 December, 1981 ; QMJ40100, Charters Towers , 83 km NNW, NEQ (19° 33' 42" S, 145° 42' 24" E), 4 December, 1981 ; QMJ69486, Pentland, CQ (20° 32' S, 145° 24' E), 9 March, 1999; QMJ74899, Lake Louisa , NWQ (19° 54' 30" S, 144° 14' 30" E), 18 March, 1984 ; QMJ84653–84654, Myola Station , CQ (20° 04' 21" S, 145° 28' 02" E), 29 September–17 December, 2006; SAMR 54519–54521 , Lolworth, 3 km N, CQ (20° 09' 40" S, 145° 00' 02" E), 20 May, 2000.

Diagnosis. Distinguished from all other Lerista by its combination of enlarged 1st supraciliary, two loreals, usually two preoculars and a single presubocular and no broad black lateral band.

Comparison with other species. Lerista hobsoni sp. nov. can only be confused with other Lerista spp. that also possess an enlarged first supraciliary (resulting from the fusion of the first two supraciliaries). These include the Queensland Lerista wilkinsi group ( L. ameles , L. cinerea , L. storri , L. vittata , L. vanderduysi sp. nov. and L. wilkinsi ) and also L. apoda and L. stylis (both of which are no longer considered members of this group). It is separated from all of these by possessing two (vs. one) loreal scales. Lerista hobsoni sp. nov. is further separated from L. ameles and L. apoda by its hindlimb (vs. totally limbless), from L. storri by having a clawed digit (vs. stylar), from L. vittata and L. vanderduysi sp. nov. in lacking a broad, dark lateral band (vs. dark lateral band present) and from L. wilkinsi by the number of digits (1 vs. 2 toes on the hindlimb).

Description of holotype ( Fig. 7 ). SVL = 67 mm; HL = 5.4 mm, 8.1% SVL; HW = 3.4 mm, 62% HL; SE = 1.5 mm, 27% HL; eyelid free, not fused into a spectacle; EE = 2.7 mm, 49% HL; RL = 0.95 mm, 17% HL; NL = 0.9 mm, 17% HL; IN = 1.0 mm, 19% HL; EN = 1.8 mm, 34% HL; RF = 1.1 mm, 21% HL; E = 0.7 mm, 13% HL; ear minute, smaller than surrounding scales; midbody width 4.4 mm, 6.6% SVL; forelimb absent; L2 = 3.1 mm, 4.7% SVL; TL = 71 mm (with regrown tip, determined by eye). Hindlimb with a single clawed digit.

Midbody scale rows 18; NC = 34%; NaL = 20%; FN = 56%; FW = 95%; IW = 76%; PL = 58%; MV = 90%; supraoculars two; supraciliaries four ( Fig. 6 B, 8A and 8B); first supraciliary contacts preocular, second loreal, prefrontal, frontal, first supraocular and second supraciliary; frontal contacts interparietal, frontoparietal, first supraocular, first supraciliary prefrontal and frontonasal; interparietal free (not fused to frontoparietals); two loreals; prefrontal present, contacting first and second loreals, frontonasal, frontal and first supraciliary; two preoculars; single presubocular; five palpebrals, single postocular; single postsubocular; five supralabials, third supralabial bordering eye; two postsupralabials; five infralabials, two infralabials contacting postmental; four scales between last infralabial and ear; single pretemporal; temporal contacts fourth and fifth supralabials, pretemporal, second temporal and postsupralabial; three rows of enlarged chin shields; primary chin shields in point contact; secondary chin shields separated by one scale; tertiary chin shields separated by three scales ( Fig. 8 C); four enlarged nuchal scales; 106 paravertebrals; two enlarged preanals; L2B = 9; six subdigital lamellae under single digit, four supradigitals.

Notes. In the holotype (QMJ93709), the prefrontal contacts both loreals but not the preocular, a condition that was otherwise seen in only two of the ten paratypes. Despite this, QMJ93709 was chosen as holotype because there was a genetic sample available for it and it features in our phylogeny ( Fig. 2 ). It is the best preserved individual in the series and typical in all other aspects of scalation. Specimens QMJ40098–40100 are also paratypes of Lerista cinerea . Greer et al. (1983) mention that the paratypes from Battery Station differ from other L. cinerea populations in having two (vs. three) phalanges on the single hind digit and a lower presacral vertebral count (46–47 vs. 48–49). We have assessed these characters over a larger sample and found there to be no consistent differences between L. cinerea and L. hobsoni sp. nov.

Variation. Sample size is 11 unless otherwise noted: SVL = 30–68 mm (54 ± 10 mm); HL = 7–13% SVL (9 ± 1%); HW = 53–73% HL (61 ± 6%); SE = 18–31% HL (26 ± 4%); EE = 44–56% HL (51 ± 4%); RL = 14–20 % HL (17 ± 1%); NL = 16–21% (18 ± 1%); IN = 17–24% HL (21 ± 2%); EN = 27–34% HL (31 ± 2%); RF = 20–28% HL (24 ± 2%); E = 13–20% HL (16 ± 2%); MW = 5–9% SVL (7 ± 1%); L2 = 4–9% SVL (6 ± 1%); TL = 92–119% SVL (100 ± 13%, n = 4 original tails, all others regrown). Hindlimb with a single clawed digit.

Midbody scale rows 18; NC = 27–43% (33 ± 5%); NaL = 19–29% (23 ± 3%); FN = 48–65% (56 ± 5%); FW = 79–105% (92 ± 8%); IW = 61–85% (75 ± 8%); PL = 50–73% (62 ± 7%); MV = 56–79% (65 ± 11%); prefrontal contacts preocular, second loreal, frontonasal, frontal and first supraciliary (in QMJ40098 the prefrontal fails to contact the preocular, in SAMR54519, SAMR54521 and QMJ93709 the prefrontal contacts the first loreal but not the preocular); first supraciliary contacts preocular, second loreal, prefrontal, frontal, first supraocular and second supraciliary (in QMJ69486 the first supraciliary contacts the presubocular but fails to contact the preocular, in QMJ74899 the first supraciliary contacts both the presubocular and preocular and in QMJ84654 the first supraciliary fails to contact both the presubocular and the preocular); two preoculars (QMJ74899 has only one preocular); 4–5 palpebrals (mode = 4); usually two infralabials (n = 10) contacting postmental, rarely one (n = 1, QMJ54519); 4–5 scales between last infralabial and ear (mode = 4); temporal contacts fourth and fifth supralabials, postocular, pretemporal, second temporal and postsupralabial (sometimes fails to contact postocular, n = 2); primary chin shields narrowly separated or in point contact (broadly contacting in one only, QMJ74899); 3–5 enlarged nuchal scales (mode = 4); 93–106 paravertebrals (mode = 99); L2B = 6–11 (mode = 10); 4–6 subdigital lamellae under single digit (mode = 6); 3–4 supradigitals (mode = 4); 80–96 subcaudals (mode = 91, n = 9). Presacral vertebrae 46–51 (mode = 47, n = 5); two or three phalanges (n = 5); 48 caudal vertebrae (n = 1).

Colouration in preservative ( Fig. 7 ). Dorsal surfaces of head, body and tail beige to greyish-brown. Body with a series of chocolate-brown streaks that form four to six broken, longitudinal lines; those on scale rows one (paravertebral) to four being the strongest. These are narrowest and most prominent on rows one to three and broader but more diffuse on the lower flanks. Lines one and two commence on the nuchal region, line three begins behind the upper posterior edge of the eye and row four begins slightly above the ear. The lines continue on the tail but are obscure or absent along its lateral surfaces. The head shields have a narrow opaque edge, which forms a pale straw-coloured margin, and are marked with scattered dark flecks. An irregular dark zone is present on the loreal region and along the dorsal margin of the supralabials. The ventral surfaces are off-white with a pale grey diffusion (body) or cream (tail). The underside of the tail has scattered dark flecks along its outer edges and in some specimens the central basal portion is distinctly flecked. Regenerated tails are dark above and below and lack the longitudinal rows of dark flecks that are seen on original tails.

Colouration in life (as different from colouration in preservative). As for spirit specimens but the base colour is silvery grey (fades to pale brown in spirit).

Etymology. Named for Rodney Grant Hobson of the Queensland Parks and Wildlife Service, for his significant contribution to the understanding and conservation of Queensland’s reptile fauna.

Distribution and habitat ( Figs. 1 and 9 ). Lerista hobsoni sp. nov. has been recorded from scattered open forest localities in the Upper Burdekin Drainage Basin.

Figures

FIGURE 1. Map of collection localities for Lerista cinerea (red), Lerista hobsoni sp. nov. (orange), Lerista vanderduysi sp. nov. (aqua) and Lerista vittata (dark blue). Large symbols indicate type localities; symbols with a dark centre indicate genetic samples as well as voucher specimens. Inset, map of Australia showing study area (Google © 2016; Image Landsat Data S 10, NOAA, U. S. Navy, NGA, GEBCO).

FIGURE 2. Majority rule consensus tree of Queensland Lerista species and outgroup taxa based on four independent runs of the concatenated data set combining multiple loci (12 S, 16 S, ND 4, flanking tRNAs and nuclear ATPs β). Branches with <60 % support were collapsed and posterior probabilities are indicated above the branches. The letter codes falling below four of the branches (A, B, B 1 and B 2) are the clades referred to in the text. Scale bar represents 5 % of uncorrected sequence divergence.

FIGURE 6. (A) Lerista vanderduysi sp. nov. (QMJ 79057, holotype) and (B) Lerista hobsoni sp. nov. (QMJ 93709, holotype) preocular and loreal scale arrangement. 1 – 4 = supraciliaries, L = loreal, PO = preocular, PS = presubocular, PT = pretemporal, S 3 = third supralabial, SO 1 – SO 2 = supraoculars.

FIGURE 7. (A) Lerista hobsoni sp. nov. preserved (QMJ 93709, holotype), (B) dorsal view of head, (C) lateral view of head (photos by P. Waddington, QM).

FIGURE 8. Lerista hobsoni sp. nov. head scalation (QMJ 93709, holotype), (A) lateral view, (B) dorsal view, (C) ventral view.

FIGURE 9. Lerista hobsoni sp. nov. type locality, Rubbish Tip Rd, Pentland, CQ (photo by A. Amey).