Antaioserpens warro ( De Vis 1884)

Peck, Patrick J. Couper Stephen R., Emery, Jon-Paul & Keogh, J. Scott, 2016, Two snakes from eastern Australia (Serpentes: Elapidae); a revised concept of Antaioserpens warro (De Vis) and a redescription of A. albiceps (Boulenger), Zootaxa 4097 (3), pp. 396-408 : 398-401

Antaioserpens warro ( De Vis 1884)

WARREGO BURROWING SNAKE ( Figs 1 , 2 A, 3, 4)

Specimens examined. Holotype: QM J188 ( Fig. 1 ) Warro Stn, Port Curtis. QM J78486 , Hill St, Charleville (26°24'S, 146°14'E), Qld; QM J93427 , Orkadilla State Forest (26°05'57"S, 147°13'01"E), Qld.

Diagnosis. A. warro is distinguished from all other Australia elapid snakes by the following suite of characters: eyes small; snout weakly shovel shaped, rostral scale lacking an acute transverse cutting edge; nasal and preocular scale separated by prefrontal / supralabial contact; two primary temporal scales; 15 midbody rows; subcaudals divided; a black bar between the eyes and another broad black bar across the nape; dorsal body scales irregularly dark-edged producing a speckled pattern.

Description. A small fossorial elapid (SVL 260–410 mm n = 3). Eye small; its diameter subequal, or less, than a straight line vertical distance to the ventral edge of subocular supralabial. Rostral large, about twice as broad as deep; weakly shovel-shaped and lacking an acute transverse cutting edge. Nasals in contact with 1st two supralabials, undivided. Internasals smaller than prefrontals which extend laterally contacting the 2nd or 2nd and 3rd supralabials. Nasal separated from preocular. Frontal longer than its distance from tip of snout and subequal in length to parietals (width 54.9–66.3% length). Preocular 1. Postocular 2. Supralabials 6. Temporals 2 + 2; lower primary temporal squarish and notched between the dorsal edges of 5th and 6th supralabials. Two pairs of chin shields, the 1st in broad contact with the first three infralabials. Midbody scale rows 15. Ventrals 139–150 (mean = 144, n = 3). Anal divided. Tail short (6.5–7.7% SVL, mean = 7.2, n = 3); Subcaudals 15–17 (mean = 15.7, n = 3), all divided. Colour pattern of holotype (QMJ 188). The holotype is now totally faded with the only record of its original pattern being the following brief description: ‘Brown, many of the scales irregularly edged with darker, producing a speckled appearance. On the nape, a very broad lunated collar. Upper surfaces of head, except tips of the occipitals, dark, but paler than nuchal collar’ ( De Vis, 1884a). This description is in all ways consistent with the appearance of the recently collected specimens (QM J78486 & QM J93427 ) discussed below. Colour pattern of recent spirit specimens. Head with a distinct blackish hood that extends from the posterior margin of the parietals, or slightly beyond, to the tip of the snout and becomes increasingly diffuse on the prefrontals, internasals and rostral. Temporal region dark. Supralabials pale with irregular darker edges and flecks; marbled anteriorly. A broad, black collar on neck, ~ 6–8 scales long and ~ 12 scales wide; separated from head pattern by ~ 3–4 rows of paler scales. Body tan to olive brown above, each scale marked with irregular dark edging that produce a speckled pattern. A narrow, dark line sometimes present on caudal vertebral scales (3/ 5 specimens). Venter off-white, with some dark blotching along outer edges of ventral scales. Chin shields and lower labials marbled with brown. Colour pattern of additional material for which there are no vouchers. The specimen from Charleville that was observed, but not photographed, is consistent with the above descriptions. The Mitchell specimen ( Fig. 3 ) is similar in most respects except the head markings are less extensive, only reaching back as far as the mid- parietals. The snout markings are also more diffuse.

Comparison with similar species. Antaioserpens warro is readily distinguished from its only congener, A. albiceps , by differences in colour pattern (dorsal scales with irregular dark edging producing a speckled appearance in A. warro vs. dorsal scales with even dark edges producing a reticulated pattern in A. albiceps ). It is distinguished from all other members of the Vermicella subgroup ( Greer 1997)— Brachyurophis , Neelaps , Simoselaps and Vermicella in possessing two (vs. one) primary temporal scales.

Distribution. ( Fig. 5 ). All recent records come from three localities in south central Qld; Charleville (26°24'S, 146°14'E), Mitchell (26°29'S, 147°28'E) and Orkadilla State Forest (north of Morven 26°05'57"S, 147°13'01"E).

Habitat. ( Fig. 6 ). All recent specimens have been recorded from the eastern edge of the Brigalow Belt South and proximate areas of the Mulga Lands Bioregion. QM J93427 , from Orkadilla State Forest, was collected from Poplar Box ( Eucalyptus populnea ) / Cypress Pine ( Callitris glaucophylla ) shrubby woodlands with a grassy ground cover on medium to coarse-grained sediments ( Sattler & Williams 1999). The Charleville and Mitchell specimens are without habitat descriptions but Poplar Box woodlands similar to the above description also occur at these locations. That one of the Charleville specimens came from a footpath in town suggests that the species can persist, to some degree, in human-impacted habitats.

Comments. We propose Warrego Burrowing Snake as a common name for this species after the name of the highway that traverses the recent collection sites. The name North-eastern Plain-nosed Burrowing Snake used by Cogger (2014), but first proposed by Ehmann (1992), refers to A. albiceps .

Figures

FIGURE 1. Holotype of Cacophis warro De Vis 1884, QM J 188, Warro Station, Port Curtis, Qld (image: Peter Waddington, Qld Museum).

FIGURE 2. (A) Dorsal scales of QM J 93427 from south central Qld showing irregular dark edging producing a speckled appearance. (B) Dorsal scales of QM J 57666 from north-eastern Qld with even dark edges producing a reticulated pattern (images: Peter Waddington, Qld Museum).

FIGURE 3. Antaioserpens warro, from Mitchell region (26 ° 29 ' S, 147 ° 28 ' E) Qld (image: Jamie Gover).

FIGURE 5. Distribution of A. albiceps ● (records from Atlas of Living Australia), holotype of Cacophis warro ■ and A. warro (▲).

FIGURE 6. Habitat of A. warro; Poplar Box (Eucalyptus populnea) / Cypress Pine (Callitris glaucophylla) shrubby woodlands, Orkadilla State Forest (26 ° 05 ' 57 " S, 147 ° 13 ' 01 " E) Qld (image: Stephen Peck).