Lerista parameles, Amey & Couper & Wilmer, 2019

Amey, Andrew P., Couper, Patrick J. & Wilmer, Jessica Worthington, 2019, Two new species of Lerista Bell, 1833 (Reptilia: Scincidae) from north Queensland populations formerly assigned to Lerista storri Greer, McDonald and Lawrie, 1983, Zootaxa 4577 (3), pp. 473-493 : 477-481

Redescription of Lerista storri Greer, McDonald and Lawrie, 1983

Mount Surprise Slider

( Figs. 3 , 4 & 5 )

Holotype. QM J39480 , Springfield Station , NEQ (17°56'50"S, 144°24'25"E), 19 Aug, 1979.

Paratypes. AMS R44772–73, Chillagoe Post Office , 14.9 km SE, NEQ (17°13'S, 144°33'E), 17 June , 1976 [now referred to Lerista parameles sp. nov. and excluded from the diagnosis and description below]; QM J39481 , Springfield Station , NEQ (17°56'50"S, 144°24'25"E), 22 August , 1981.

Other material examined. QM J85022 , Almaden–Mount Surprise railway line, NEQ (17°56'55"S, 144°24'28"E), 4 June , 2006; QM J94325 , Springfield Station , NEQ (17°56'52"S, 144°24'30"E), 22 September , 2015; QM J94333 , Springfield Station , NEQ (17°56'59"S, 144°24'27"E), 24 September , 2015.

Diagnosis. Distinguished from all other Lerista by the complete absence of a forelimb, hindlimb styliform <2.5% SVL, interparietal distinct from the frontoparietals, prefrontals absent, four supraciliaries and anterior chin shields with an intervening scale.

Comparisons. This species is very close morphologically to L. alia sp. nov. It can usually be distinguished by its shorter hindlimb, but there is overlap in this character (range: 1.70–2.46% SVL vs. 2.33–4.49% SVL). This species is almost patternless, with very vague to absent bands of darker pigment running along the body, strongest anteriorly. In L. alia sp. nov., discrete dark flecks are always present, forming more or less distinct longitudinal lines, strongest anteriorly (for comparison, see Fig. 3 ). The two species are separated geographically by about 60 km, with L. alia sp. nov. centred on Bulleringa National Park and L. storri known only from Springfield Station (see Fig. 1 ). Of those species of Lerista with no forelimb and a stylar or single digit hindlimb (18 species), only four other species have four supraciliaries, L. cinerea , L. hobsoni , L. vanderduysi and L. vittata . These four species all have a longer hindlimb (>4% SVL) with a distinct, clawed digit and usually have two infralabials contacting the postmental (vs. a single infralabial in L. storri and L. alia sp. nov.).

Description of holotype. Adult female; SVL = 66 mm; HL = 5.6 mm, 8.5% SVL; HW = 3.2 mm, 57% HL; SE = 1.1 mm, 20% HL; eyelid free (not fused into a spectacle); EE = 2.6 mm, 45% HL; RL = 0.98 mm, 17% HL; NL = 1.1 mm, 20% HL; IN = 1.2 mm, 22% HL; EN = 1.8 mm, 32% HL; RF = 1.3 mm, 23% HL; E = 0.74 mm, 13% HL; ear minute, smaller than the surrounding scales; MW = 4.0 mm, 6.1% SVL; forelimb absent; L2 = 1.2 mm, 1.8% SVL; TL = 73 mm, 111% SVL (original, determined by X-ray). Hindlimb styliform, no evidence of a digit.

Midbody scale rows 20; NC = 55%; NaL = 17%; FN = 109%; FW = 88%; IW = 114%; PL = 56%; MV = 50%; two supraoculars; four supraciliaries, all in contact, first enlarged; first supraciliary contacts preocular, loreal, frontonasal, frontal, first supraocular and second supraciliary; frontal contacts interparietal, frontoparietal, first supraocular, first supraciliary and frontonasal; interparietal free (not fused to frontoparietals); single loreal; prefrontal absent; single preocular; single presubocular; four palpebrals; single postocular; single postsubocular; five supralabials; third supralabial bordering eye; single postsupralabial; five infralabials, single infralabial contacting postmental; four scales between last infralabial and ear; single pretemporal; temporal contacts fourth and fifth supralabials, postocular, pretemporal, parietal (point contact), second temporal and lower temporal; three rows of enlarged chin shields; primary chin shields separated by intervening scale; secondary chin shields separated by one scale; tertiary chin shields separated by three scales; four enlarged nuchal scales; 107 paravertebrals; two enlarged preanals; L2B = 3.

Variation. The two paratypes referred to L. parameles sp. nov. are excluded from this description. Sample size is therefore four unless otherwise noted: SVL = 47–67 mm (58 + 7 mm); HL = 7.8–8.9% SVL (8.5 + 0.3%); HW = 56–68% HL (63 + 4%); SE = 20–28% HL (24 + 3%); EE = 45–54% HL (49 + 2%); RL = 15–19 % HL (17 + 1%); NL = 19–23% HL (21 + 1%); IN = 19–24% HL (22 + 2%); EN = 31–34% HL (32 + 1%); RF = 23–28 % HL (25 + 2%) ; E = 13–18% HL (15 + 1%); MW = 5–7% SVL (6 + 1%); L2 = 1.7–2.5% SVL (2.1 + 0.4%); TL = 96% SVL (single original tail, QM J85022 , determined by X-ray, all others regrown) .

Midbody scale rows 20 (18, QM J94325 only); NC = 40–55% (47 + 6%); NaL = 13–23% (18 + 4%); FN = 48– 110% (82 + 29%); FW = 87–106% (96 + 8%); IW = 81–114% (98 + 9%); PL = 50–66% (59 + 6%); MV = 49–79% (63 + 10%); four supraciliaries, first enlarged, first three in contact, fourth separate at posterior edge of eye below last supraocular; 3–5 palpebrals (mode = 4); temporal contacts fourth and fifth supralabials, postocular, pretemporal, second temporal and lower temporal (sometimes no contact with postocular, N = 2); 3–5 enlarged nuchal scales (mode = 4), 101–115 paravertebrals; L2B = 2–4 (mode = 4); hindlimb styliform, no evidence of a digit or claw; 104 subcaudals (N = 1).

Colouration in preservative ( Figs. 3 & 4 ). The dorsal surfaces of the head, body and tail are pale silvery grey. The body (paravertebrals and adjacent scale rows) is largely without pattern but the flanks (rows three to six or four to seven) are marked with four diffuse longitudinal stripes. Ventral surface cream to straw coloured. The head shields are very weakly mottled and a dark zone is present from the secondary temporal, through the eye and extending forward to the ventral edge of the nasal. The tail is strongly marked with longitudinal rows of dark streaks and heavily flecked on the ventral surface.

Colouration in life (as different from colouration in preservative, Fig. 5 ). As for spirit specimens but the ground colour is more lustrous.

Distribution and habitat ( Figs. 1 and 6 ). Known only from Springfield Station, N of Mount Surprise, NEQ. This falls within the Lynd River catchment of the Mitchell River drainage system in the Einasleigh Uplands Bioregion. The Extent of Occurrence (EOO, as defined by IUCN 2012) is less than 1 km 2. The species was collected in the following Regional Ecosystems (Queensland Government Environment and Science 2018):

9.5.8: Woodland to open woodland of Eucalyptus cullenii and/or E. leptophleba +/- Corymbia erythrophloia +/- Erythrophleum chlorostachys . Eucalyptus tardecidens may also occur as a subdominant in northern extent of this regional ecosystem. A sparse shrub layer includes Petalostigma spp., Melaleuca spp., Grevillea spp., Alphitonia pomaderroides and Denhamia cunninghamii . The sparse to dense ground layer is dominated by Heteropogon contortus and Sarga plumosum . Occurs on undulating plains in valleys in ranges on Tertiary/Quaternary soils overlying granite and metamorphic geologies.

9.12.3: Woodland to low woodland of Eucalyptus chartaboma and/or E. crebra or E. cullenii or E. granitica +/- Corymbia erythrophloia +/- E. tetrodonta +/- Erythrophleum chlorostachys +/- C. dallachiana +/- C. clarksoniana . There can be sub-canopy including canopy species, Grevillea glauca and Petalostigma pubescens . The shrub layer is sparse to open and includes juveniles of canopy species, Grevillea spp., Petalostigma spp., Melaleuca viridiflora, Alphitonia pomaderroides and Planchonia careya . The dense ground layer is dominated by Heteropogon spp., Themeda triandra , Schizachyrium fragile and Sarga plumosum . In the north of the bioregion the Eucalyptus crebra is replaced by E. cullenii . Small areas with C. trachyphloia or E. similis may occur. Occurs in patches on footslopes, low hills, crests and ridges.

General ecology. Specimens were found in loose soil under logs and other debris. As far as is known, it feeds on small arthropods.

Comments. The original diagnosis given in Greer et al. (1983) is similar to that given in the same publication for Lerista vittata and does not distinguish the two taxa. Lerista storri is properly diagnosed from L. vittata by a shorter hindlimb (<3% SVL vs.>4%SVL) lacking a distinct, clawed digit and a single infralabial contacting the postmental (vs. usually two).

The major field guides Cogger (2014), Wilson (2015) and Wilson and Swan (2017) all refer to L. storri as the Chillagoe Fine-lined Slider. However, we have found the Chillagoe population is referrable to Lerista parameles sp. nov. and we therefore believe the name is more suited to this taxon. Accordingly, we prefer the name Mount Surprise Slider for L. storri .

Conservation Status. This species is listed as Vulnerable by Queensland’s Nature Conservation Act ( Queensland Government 1992) and Near Threatened by the IUCN ( Vanderduys et al. 2018). However, these assessments were based on the broader concept of L. storri which included the populations split off here as L. alia sp. nov. and L. parameles sp. nov. With our revised narrower concept of the species, it is known from only a single locality less than 1 km 2 in extent, which is not in a protected reserve. Here it is threatened by compaction of sandy soil through intensification of cattle grazing, and by multiple invasive plant species (including Buffel Grass, Grader Grass, Indian Couch, and Rubber Vine) potentially altering soil structure. Population trends are unknown but inferred to be downwards. Therefore, we believe it qualifies as Critically Endangered under IUCN guidelines ( IUCN 2012).

Figures

FIGURE 1. Map of collection localities for Lerista ameles (purple diamonds), L. alia sp. nov. (blue triangles), Lerista parameles sp. nov. (orange crosses) and L. storri sensu stricto (brown squares).

FIGURE 3. Preserved holotypes of Lerista alia sp. nov. (A, QM J94337) and Lerista storri s.s. (B, QM J39480), showing difference in degree of pattern; distinct dark flecks in L. alia sp. nov. vs. absence of discrete patterning in L. storri s.s. (Photo: P. Waddington).

FIGURE 4. Preserved holotypes of Lerista parameles sp. nov. (top, QM J95783), Lerista alia sp. nov. (middle, QM J94337) and Lerista storri s.s. (bottom, QM J39480). Scale bar = 1 cm (photo: P. Waddington).

FIGURE 5. Lerista storri s.s. in life (QM J94333, photo: P. Waddington).

FIGURE 6. Collection locality of L. storri s.s. (QM J94325, photo: A. Amey).