A new species of Anilios (Scolecophidia: Typhlopidae) from Central Australia
Author
Shea, Glenn M.
text
Zootaxa
2015
4033
1
103
116
journal article
10.11646/zootaxa.4033.1.5
c7200ffe-d1ed-4479-942e-bc5b2d099a73
1175-5326
245550
D3D9BFAA-F967-4342-ABFC-BA3EAEA40E43
Anilios fossor
sp. nov.
Figs. 1–3
Holotype
.
NTM
R14324 (field tag JCR30), Glen Annie, Ruby Gap Nature Park, Northern Territory,
Australia
, collected
15.x.1989
by J.R. Cole. The coordinates of the
type
locality are given in the
NTM
database as
23°28'S
135°00'E
. However, from the map provided by the
Gibson
et al
. (1992)
, the coordinates of Glen Annie are closer to
23°28'S
134°58'E
, at an altitude of
ca
500 m
(from Google Earth).
Diagnosis.
Anilios fossor
is distinguished from all other described species in the genus (
sensu
Pyron & Wallach 2014
) by the combination of 20 midbody scale rows, a rounded snout in lateral profile (lacking any rostroventral angulation), a nasal cleft contacting the second supralabial ventrally, but not extending to the dorsal surface of the head, and a large, round rostral scale. For more detailed comparisons with other species, see below.
FIGURE 1.
Holotype of
Anilios fossor
.
Description of
holotype
(the only known specimen).
Snout rounded in dorsal profile, with a very slight inflation of the nasal region providing a very weakly trilobed appearance. Rostral almost as broad as long, round with a slightly truncate posterior margin, maximum width 69% of head width at level of centre of eyes. Rostral overlaps nasals and frontal; nasals broadly separated by frontal; frontal wider than long, wider than postfrontal, overlapping supraoculars and postfrontal; supraoculars moderately separated by frontal-postfrontal suture; postfrontal overlaps parietals and interparietal; parietals moderately separated by postfrontal-interparietal suture, but more narrowly than separation between supraoculars. Dorsolaterally, supraoculars wider than long, extensively overlapping ocular, with narrower overlaps of postfrontal and parietal; parietal wider than long, of similar width to supraocular, and overlapping interparietal, upper postocular, and first scale of third (left side) or second and third (right side) longitudinal scale rows.
FIGURE 2.
Headshields of the holotype of
Anilios fossor
in dorsal view. Scale bar = 2mm.
Snout evenly rounded in lateral profile, slightly depressed. Nasal overlaps frontal, supraocular and preocular; preocular about 2/3 width of nasal, posterior border evenly convex (no dimple to correspond to underlying eye) and overlapping supraocular and ocular; ocular wider than preocular, subequal in width to nasal, and overlapping parietal, two postoculars, and fourth supralabial. Eye moderate, pupil distinct, deep to (under) junction of supraocular, preocular and ocular scales, centre of eye just posterior to preocular.
Ventral rostral lobe moderately broad with rounded posterior margin. Nasal cleft short, from second supralabial, across anterior margin of nostril, then extending about 2/3 of the residual distance towards the rostral, not extending onto the dorsal surface of the head. First three supralabials of subequal length, first two narrow, third as tall as long. First supralabial overlapped by rostral lobe of nasal; second supralabial overlapped by rostral and caudal lobes of nasal, and preocular; third supralabial overlapped by preocular, but overlapping ocular (T-III pattern of
Wallach 1993
); fourth supralabial much longer than others, equal in height to third supralabial, and overlapped by ocular, but overlapping lower postocular. Postoculars two, equal in size to scales in succeeding longitudinal scale row.
Mental of similar size to adjacent infralabials and smaller than gulars; first three infralabials successively lower, fourth infralabial separated from third infralabial by first scale of third ventral longitudinal scale row. No visible marginal glands associated with head shields. Scale organs scattered over rostral and nasal scales, becoming coarser and much more sparsely distributed over supralabials, preocular, ocular and parietal. Longitudinal scale rows at midbody 20; total dorsal scale rows 514, body dorsal scale rows 503; subcaudals 11. SVL
240 mm
(anterior body of
holotype
slightly concertinaed, so that measured SVL may be slightly underestimated); body width (BW)
4.7 mm
(BW/SVL 0.0196); tail length (TL)
5 mm
(TL/SVL 0.0208; TL/BW 1.06), terminal spine prominent. In preservative, pale yellow brown dorsally, yellow ventrally; no aggregations of pigment forming any stripes. Adult female, with thickened and obliquely pleated right oviduct; left oviduct absent.
Etymology
. From the Latin
fossor
, a miner, in allusion to the fossorial habits of the genus and the
type
locality, where the numerous garnets in the bed of the Hale River, misidentified as rubies, sparked the Northern Territory's first mining rush (
Gibson
et al
. 1992
). The species epithet is a noun in apposition.
Comparisons with other species.
Anilios fossor
keys to
A. splendidus
(
Aplin 1998
)
using the key provided by
Cogger (2014)
, in having the nasal cleft contacting the second supralabial, 20 midbody scales, a head smoothly rounded in outline from above, ventral surface pale, the nasal cleft not extending onto the dorsum of the head or to the rostral to divide the nasal, and the snout rounded in profile (although
splendidus
has an angulate rostral in profile,
contra
the character state given in the key;
Aplin 1998
). However, it differs from
A. splendidus
in its much smaller size (mature female with SVL =
240 mm
,
vs
SVL of only known specimen, also a mature female,
498 mm
), paler coloration (pale yellow-brown dorsally
vs
dark grey-brown above, sharply demarcated from the pale venter), rounded snout in lateral profile (
vs
strongly angulate), larger eye, and much greater number of dorsal scales (dorsal scales to level of cloaca 503
vs
377) (
Aplin 1998 for comparative data
). Additionally,
A. splendidus
is only known from North-West Cape, Western
Australia
, over half a continent away.
It shares the greatest overall similarity with
A. wiedii
(
Peters 1867a
)
, a species which is similar in size (SVL of mature females, the larger sex,
175–322 mm
, mean =
232.5 mm
, median =
231 mm
, n = 65), coloration (pale yellow-brown in preservative) and number of midbody scales (20), and also has the nasal cleft contacting the second supralabial and a rounded snout in dorsal and lateral profile. It differs from
A. wiedii
(
Fig. 5
) in having a much larger, more rounded rostral scale, in the nasal cleft not extending to the dorsal surface of the head (
vs
extending well onto the dorsal surface, then extending medially towards the rostral to almost or completely divide the nasal), and in having more dorsal scales (514
vs
379–442 for males and 421–469 for females). The only individuals of
A. wiedii
with dorsal scales greater than 434 for males and 452 for females among the 135 individuals examined are from a single sample of 11 individuals from "Darling River Floods". This series was part of a major collection made by the Australian Museum collector Robert Helms between
May and June 1890
. Most of the registration entries for this collection do not specify where along the Darling River these collections were made. However, one series (AM R6457–67) does more specifically note that the collection was made between Bourke and Wilcannia, and a contemporary newspaper report (Anon 1890) notes that Helms spent nearly two weeks in
June 1890
collecting amongst flood debris at Tallywaka (now Talyawalka, an overflow anabranch paralleling the Darling River near Wilcannia). This is the westernmost record of
A. wiedii
, but could represent individuals washed downstream from further east. Despite the somewhat higher dorsal scale counts of these specimens, which are geographically intermediate between the distribution of
A. wiedii
and
A. fossor
, in other respects this sample is typical of
A. wiedii
, and does not represent a morphological intermediate between the two species. The geographic distance between the only known locality for
A. fossor
, and
A. wiedii
at Talyawalka is
1250 km
, with the Simpson and Strzelecki Deserts in the intervening area.
Five other species of
Anilios
have a distribution that reaches central
Australia
:
A. bituberculatus
(
Peters 1863
)
,
A. centralis
(
Storr 1984
)
,
A. diversus
(
Waite 1894
)
,
A. endoterus
(
Waite 1918
)
and
A. grypus
(
Waite 1918
)
, and hence could be sympatric with
A. fossor
.
Anilios bituberculatus
has a strongly trilobed snout in dorsal profile which is angulate in lateral profile, and has a much narrower rostral scale.
Anilios centralis
has a hooked snout in lateral profile, a narrower rostral scale (see
Fig.
1
in
Storr 1984
), more subcaudal scales (12–20, the lower end of the range presumably representing females) and slightly fewer dorsal scales (425–494) (data from
Storr 1984
;
Pyron & Wallach 2014
).
Anilios diversus
has a nasal cleft contacting the preocular scale, a very narrow rostral scale, and fewer transverse scale rows (dorsal scales 403–465
fide
Pyron & Wallach 2014
; ventral scales 389–457
fide
Storr 1981
;
Aplin 1998
notes that ventral scales are roughly comparable to dorsal scales counted to the level of the cloaca).
Anilios endoterus
has 22 rows of scales at midbody, a nasal cleft joining the preocular, a snout that is angular in lateral profile, and fewer dorsal scale rows (422–463;
Pyron & Wallach 2014
;
Shea
et al
. 2000
). Central Australian populations of
A. grypus
have a strongly hooked snout in lateral profile, 18 midbody scales, a narrow rostral scale, and a dark head and tail.
FIGURE 3.
Headshields of the holotype of
Anilios fossor
in left lateral and ventral views. Scale bar = 2mm.
An additional five species of
Anilios
from semiarid and mesic parts of
Australia
share with
A. fossor
the combination of 20 midbody scales, and the nasal cleft contacting the second supralabial:
A. broomi
(
Boulenger 1898
)
,
A. leucoproctus
(
Boulenger 1889
)
,
A. pinguis
(
Waite 1897
)
,
A. sylvia
(
Ingram & Covacevich 1993
)
and
A. waitii
(
Boulenger 1895a
)
. Of these,
A. waitii
of the semiarid and arid parts of Western
Australia
has a hooked rostral in lateral profile and a trilobed snout in dorsal view, and
A. pinguis
of south-western
Australia
is a much larger species (SVL up to
491 mm
;
Aplin 1998
) with an angulate snout in lateral profile, rostral much longer than wide ("urn-shaped";
Storr, 1981
), many fewer dorsal scales (to cloaca, 280–388,
Aplin 1998
) and a dark brown to black dorsal color.
Anilios sylvia
, a species confined to a small part of the southern Queensland coast, is a smaller species (maximum SVL
175 mm
), with many fewer transverse scale rows (ventral scales 271–320), nasal cleft extending onto the head dorsum, smaller rostral scale (of similar size and shape to
A. wiedii
) and a very dark dorsum (
Ingram & Covacevich 1993
).
Anilios leucoproctus
, a species restricted to Cape York and the Torres Strait Islands, similarly has fewer dorsal scale rows (386–426
fide
McDowell 1974
; 377–394
fide
Shea 1999
), is darkly pigmented both dorsally and ventrally, has a narrower rostral scale, and has well-developed glands along the margins of the head shields (
McDowell 1974
), while
Anilios broomi
, a species of the Wet Tropics of Queensland, from the Atherton Tableland to Cooktown, is strongly striped dorsally, has fewer dorsal scale rows (456–460
fide
McDowell 1974
; 445-510
fide
Pyron & Wallach 2014
), and a nasal cleft that extends onto the dorsal surface of the head to divide or nearly divide the nasal.
All other
Anilios
species either have fewer midbody scales (16:
A. leptosoma
(
Robb 1972
)
,
A. longissimus
(
Aplin 1998
)
,
A. minimus
(
Kinghorn 1929
)
,
A. nema
(
Shea & Horner 1997
)
; 18:
A. affinis
(
Boulenger 1889
)
,
A. aspina
(
Couper
et al
. 1998
)
,
A. chamodracaena
(
Ingram & Covacevich 1993
)
,
A. guentheri
(
Peters 1865
)
,
A. howi
(
Storr 1983
)
, some
A. leptosoma
,
A. margaretae
(
Storr 1981
)
,
A. micromma
(
Storr 1981
)
,
A. nigricauda
(
Boulenger, 1895b
)
,
A. nigroterminatus
(
Parker, 1931
)
,
A. yampiensis
(Storr 1981))
or more midbody scales (22:
A. australis
Gray 1845
,
A. bicolor
(
Peters 1860
)
,
A. hamatus
(
Storr 1981
)
,
A. kimberleyensis
(
Storr 1981
)
,
A. nigrescens
Gray 1845
,
A. pilbarensis
(
Aplin & Donnellan 1993
)
,
A. polygrammicus
(
Schlegel 1839
)
,
A. robertsi
(
Couper
et al
. 1998
)
,
A. torresianus
(
Boulenger 1889
)
,
A. troglodytes
(
Storr 1981
)
; 24:
A. batillus
(
Waite 1894
)
,
A. ganei
(
Aplin 1998
)
,
A. ligatus
(
Peters 1879
)
,
A. unguirostris
(
Peters 1867b
)
,
A. yirrikalae
(Kinghorn 1942))
, or if they have 20 midbody scales, they have the nasal cleft contacting either the first supralabial (
A. erycinus
(
Werner 1901
)
,
A. proximus
(Waite 1893))
or the preocular (
A. ammodytes
(
Montague 1914
)
,
A. tovelli
(Loveridge 1945))
.
Distribution
. Only known from the
type
locality (
Fig. 4
), on the upper reaches of the Hale River and at the eastern extremity of the Central Australian Ranges, between the relatively low Amarata and Harts Ranges.
Due to their fossorial habits, typhlopids are generally difficult to target by normal collecting and short-term survey methods, but are instead most often collected opportunistically by long-term residents close to settled areas. This effect is enhanced in the arid zone of
Australia
, where the sparse settlement means that relatively few typhlopids are collected other than around towns and homesteads, with often large gaps between known localities. The majority of typhlopid specimens from the southern Northern Territory have been collected from the environs of Alice Springs, or near major tourist venues.
Anilios fossor
is not represented among the typhlopid material from Alice Springs in the central part of the Central Australian Ranges, and hence may not extend significantly west of the
type
locality, towards the McDonnell Ranges. The Hale River, which flows through the Ruby Gap Nature Park and could provide a dispersal route for the species, drains into the Simpson Desert, an extensive sandridge system representing a very different geomorphology to the
type
locality. Hence, it is possible that the species has a very restricted distribution.
However, I cannot exclude the alternative possibility that
A. fossor
has a more extensive distribution that is yet to be identified. Another species of arid Australian typhlopid,
A. margaretae
, was described in 1981 from a single specimen from Lake Throssel in Western
Australia
, and is generally reported as restricted to that region (e.g.,
Cogger 2014
;
Wilson & Swan 2013
), but has recently been collected opportunistically at two localities in central South
Australia
, over
750 km
to the south-east (M. Hutchinson, pers. comm.)— the intervening area has almost no permanent human settlement, and few roads.
Given the uncertainty about the distribution of the species, it is not possible to provide a conservation assessment, but there are no grounds to think there has been any significant decline in the species that may require a threatened conservation status, and the
type
locality is located in a remote nature reserve with little human impact (the locality is only accessible by four wheel drive vehicular traffic). However, further work is needed in the vicinity of the
type
locality to determine population density of this poorly known species.
FIGURE 4.
Distribution of
A. fossor
(triangle) within the Northern Territory. The nearest major settlement (Alice Springs) is marked by a square. Relief is indicated by grey shading—pale shading marks higher elevations. Northern Territory borders are 129° and 138°E and 26°S.
Habitat.
The
holotype
was collected during a fauna survey of the Ruby Gap Nature Park (
Gibson
et al
. 1992
), at which time it was identified as
Ramphotyphlops centralis
. Two specimens identified as this species were collected and lodged in the Northern Territory Museum, the
holotype
of
A. fossor
and NTM 14316. The habitat notes for these two specimens were provided by
Gibson
et al
. (1992)
as "a low, open woodland of
Eucalyptus thozetiana
on stony plains, also a woodland of
Eucalyptus camaldulensis
on sandy loam soil near the Hale River".
As
the locality for NTM 14316, which is a specimen of
A. centralis
, is Thozet Box Camp, Loves Creek Station, a locality not on the Hale River, I presume that the second habitat description applies to
A. fossor
. The
Eucalyptus camaldulensis
vegetation association is described in the same report as a woodland with upper storey of
E. camaldulensis
, midstorey absent or with scattered
Capparis spinosa
and
Acacia victoriae
, and ground story of
Cynodon dactylon
,
Brachyachne ciliaris
, and ephemeral herbs and grasses on sand and sandy loam along major creeklines. This habitat is on Cainozoic alluvium, although the general surrounds are metamorphic quartzites, amphibolites, gneisses and tonalites of the Precambrian Heavitree Quartzites and Arunta Complex.