Anilios insperatus, Venchi, Alberto, Wilson, Steve K. & Borsboom, Adrian C., 2015

Venchi, Alberto, Wilson, Steve K. & Borsboom, Adrian C., 2015, A new blind snake (Serpentes: Typhlopidae) from an endangered habitat in south-eastern Queensland, Australia, Zootaxa 3990 (2), pp. 272-278 : 273-277

Anilios insperatus sp. nov.

Fassifern Blind Snake ( Figs. 1 , 2 )

Holotype. Queensland Museum J54987 , from Warrill View, Department of Primary Industries Animal Genetic Centre Farm (2749' S, 15237' E), collected on 19 May 1992 by A. Borsboom.

Diagnosis. Anilios insperatus sp. nov. is a small, slender blind snake characterized by the following combined characters: 16 midbody scale rows, 442 paravertebral scales, snout slightly trilobed from above and bluntly angular in profile, nasal scale not completely divided, nasal cleft not visible from above and joining the second supralabial scale, small, inconspicuous eyes, located within the ocular scale at its junction with the preocular and the supraocular scales, light uniform colouration with no differentiation between dorsal and ventral surfaces.

Description. Snout slightly trilobed from above (rostral extending beyond curvature of head and an indentation present on sides of the rostral); snout bluntly angular in profile. Rostral scale from above large, elliptical, slightly longer than wide, about half the width of head, its posterior margin not reaching back to level of the eyes; ventral lobe about as long as wide, but tapering strongly towards mouth. Nasal scales from above appear slightly swollen and well separated by the prefrontal scale. Nostrils positioned ventro-laterally in lower portion of the nasal scale, about midway between the rostral and preocular. Nasal cleft extends from the second supralabials scale through nostril to a little beyond (about 1/3–1/4 the distance between nostril and rostral scale); nasal cleft not visible from above. Preocular scale narrower than ocular and nasal scales, about half the width of the nasal. Eyes small and inconspicuous, positioned within ocular scale near its junction with preocular and supraocular scales. Ocular in contact posteriorly with parietal, two postoculars and fourth supralabial. Frontal smaller than prefrontal and interparietal. Supraocular subequal in size to parietal, in broad contact anteriorly with prefrontal and in narrow contact with nasal and preocular; posteriorly in contact with ocular, parietal and frontal. Four supralabials, first smallest and overlapped by nasal, second larger and overlapped by nasal and preocular, third larger than the second and overlapping the ocular (pattern T-III sensu Wallach 1993), fourth largest, expanded posteriorly, overlapped by ocular and terminating in line with its posterior margin. Mental and postmental scales subequal. Infralabials four, second smallest. Microtubercles present in all head shields.

Measurements: Midbody scale rows 16; paravertebral scales 442; subcaudals 19; apical spine present. SVL 93.7 mm, TL 2.9 mm, BW 2.7 mm, HW 2.2 mm, RL 1.1 mm, RW 1.2 mm, ED 0.1 mm, EN 1.0 mm. Distance from tip of snout to mouth 0.8 mm. The percentage of BW/SVL is 2.88%.

Colouration (in alcohol): Uniformly cream over the dorsal and ventral surfaces, with no indication of any pigmentation on the scales. Eyes are dark but inconspicuous. The colouration in life cannot be ascertained with certainty as neither photos nor detailed notes were taken at the time of collection. However, the specimen has been stored away from light for as long as it has been in the museum collection, so it is unlikely to have faded to any degree (Patrick Couper pers. comm.).

Comparison with similar species. Only four Australian species of Anilios have 16 scales at midbody, but all are geographically distant and show the following morphological differences:

A. longissimus ( Aplin, 1998) is known only from Barrow Island, north-western Western Australia, and is an extremely elongate troglodytic species. Compared to A. insperatus , it has a squarer snout when viewed from above, more prominent eyes positioned more medially at anterolateral corner of supraocular scales, is much more slender (BW as % of SVL, 0.83% vs. 2.88%) and has more paravertebral scales (750 vs. 442).

A. minimus ( Kinghorn, 1929) , from Groote Eylandt and nearby coast of Northern Territory, has a rounded head, dark tail (often also a dark head) and a striped body pattern.

A. nema ( Shea & Horner, 1997) , from the Darwin area, Northern Territory, has a rounded snout, lower BW as % of SVL (1.08–1.75% vs. 2.88%) and its dorsal colour is darker than its venter.

A. leptosomus ( Robb, 1972) , from the mid-west coast of Western Australia, can have either 16 or 18 midbody scale rows, but has the nasal scale completely divided and the snout is sharply angular in profile with a weak to moderately strong transverse cutting edge.

No other species occurring in Queensland has 16 midbody scales and lacks pigmentation, but among those likely to be sympatric with A. insperatus sp. nov. we highlight the following differences:

A. affinis ( Boulenger, 1889) has 18 midbody scale rows. Its head is rounded dorsally and its nasal scale is completely divided.

A. ligatus ( Peters, 1879) has 24 midbody scale rows. Its head is rounded dorsally and in profile, and its nasal cleft joins the first supralabial.

A. nigrescens ( Gray, 1845) has 22 midbody scale rows. Its head is rounded dorsally and in profile, and its nasal cleft joins the first supralabial.

A. proximus ( Waite, 1893) has 20 midbody scale rows. Its nasal cleft joins the first supralabial.

A. weidii ( Peters, 1867) has 20 midbody scale rows, a rounded head, and its rostral is almost circular from above.

Additionally, all these species, except A. affinis , differ in having the nasal cleft visible from above.

Etymology. The Latin word insperatus means unexpected, unanticipated, unhoped, unlooked-for, unforeseen. This alludes to the unexpected discovery of a new species of snake in an intensively surveyed, easily accessible area less than 100 km from an Australian capital city. Used as a noun in apposition.

Distribution. Anilios insperatus sp. nov. is currently known only from the type locality, which lies 2.9 km west-north-west of Warrill View, located 69 road kilometres south-west of Brisbane, in the Fassifern Valley, southeastern Queensland, Australia ( Fig. 3 ).

Habitat. During a 1992 fauna survey ( Borsboom 1993), the holotype was found on a cleared hill-slope pasture under a small rock ( Fig. 4 ). The collecting site pre-clearing was Queensland regional ecosystem (RE) 12.8.24. This RE is still present on the hill crest ( Fig. 3 , inset). Queensland REs are coded with a three-part number, the first part representing the bioregion, the second the land zone and the third the dominant vegetation ( Neldner et al. 2012; Wilson & Taylor 2012). RE 12.8.24 is broadly defined as Corymbia citriodora subsp. variegata, Eucalyptus crebra +/- E. moluccana open forest, on Cainozoic igneous rocks especially lower slopes of rhyolite and trachyte hills ( Queensland Herbarium 2014). The dominant mapped soil at the site is a prairie soil and described as a “shallow dark hard-setting clay with slightly alkaline yellowish to reddish brown subsoil ( Fisher & Baker 1989).

Conservation. Anilios insperatus sp. nov. is known only from the holotype, despite seven attempts by the authors to locate additional specimens during 2014 and 2015. Dunn et al. (1994) report the type locality area was cleared for grazing in the 1920s, and the oldest available aerial photography confirming clearing was pre-1944.

What impact grazing has had on this snake is unknown. However, of great concern is the clearing of RE 12.8.24, the only RE the species is currently known from. Clearing of this RE has been so extensive that it is listed as ‘Endangered’ ( Queensland Herbarium 2014).

With the snake’s type locality close to the large and expanding urban areas of Brisbane and Ipswich, we recommend A. insperatus sp. nov. be regarded as being of high conservation concern. Further survey effort is required to locate more individuals in order to learn more of its habitat preferences. Until more specimens are encountered, RE 12.8.24 should be considered as essential habitat for this species, with the remnants remaining receiving full protection from clearing and other habitat degradation activities.

Figures

FIGURE 1. Anilios insperatus sp. nov.: (a) entire holotype, (b) dorsal, (c) ventral and (d) lateral views of head. Scale bar 0.5 mm.

FIGURE 2. Line drawings of the head of Anilios insperatus sp. nov. illustrating scalation in (a) dorsal, (b) ventral and (c) lateral views.

FIGURE 3. Main map: Anilios insperatus sp. nov. type locality and other Anilios species records in the vicinity of Brisbane (* ABS = Australian Bureau of Statistics). Top right inset: The past and present extent of the endangered Regional Ecosystem 12.8. 24.

FIGURE 4. Type locality of Anilios insperatus sp. nov. in July 2014.