A new species of Lobulia (Squamata: Scincidae) from Papua New Guinea
Author
Kraus, Fred
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA.
text
Zootaxa
2020
2020-05-19
4779
2
201
214
journal article
22032
10.11646/zootaxa.4779.2.3
3c1c0bd6-6689-4b6a-9eba-6eb9fcccb870
1175-5326
3833477
E7275795-8B03-4BE6-A25C-008D3325BE67
Lobulia elegans
(Boulenger)
Figures 1
A–D, 2A, B, 3A
Lygosoma elegans
Boulenger, 1897: 8
.
Type
locality:
Mt. Victoria
,
Papua New Guinea
.
Lygosoma elegantoides
Ahl, 1925: 20
(replacement name for
Lygosoma elegans
)
Lygosoma
(
Leiolopisma
)
elegans
,
Smith 1937: 224
.
Lygosoma
(
Leiolopisma
)
elegantoides lobulus
, Loveridege 1945: 49
.
Scincella elegantoides
,
Mittleman 1952: 24
.
Lobulia elegans
Greer, 1974: 9
.
Lobulia elegantoides
Shea & Michels, 2008: 738
.
Material examined for rediagnosis.
Papua New Guinea
:
Central Province
:
Mt. Victoria
(
BMNH 96.10
.31.9,
holotype
),
Mondo
,
09.25ºS
,
147.41ºE
,
700 m
a.s.l.
(
BMNH
1935.5.10.143), Fane,
8.5530ºS
,
147.0833ºE
,
1400–1440 m
a.s.l.
(
BPBM 18691–93
)
,
NW slope
Mt. Obree
,
9.4456ºS
,
147.9982ºE
,
1330–1450 m
a.s.l.
(
BPBM 19594
)
.
Diagnosis.
A moderately sized species of
Lobulia
, adult SVL
59–66.5 mm
; with a dorso-ventrally flattened body, distinct frontoparietals, two supralabials posterior to subocular, scales of temporal region not highly fragmented, lobules present on anterior margin of ear opening, subdigital lamellae 22–28 under 4th toe, mid-body scale rows 30–32, paravertebral scales 52–54, mid-dorsum with two rows of large dark-brown spots, top of tail base with one row of large dark-brown spots, sides brown with rows of small dark-brown spots, distinct pale dorsolateral stripe absent, light field on abdomen that lacks brown spotting ten scales wide, and under thighs and precloacal region white, without brown spotting.
Lobulia elegans
can be distinguished from the other five species currently placed in the genus as follows:
L. elegans
differs from
L. brongersmai
in having separate (vs. fused) frontoparietals; from
L. alpina
Greer, Allison & Cogger
and
L. subalpina
Greer, Allison & Cogger
in having two (vs. three) supralabials posterior to the subocular supralabial and lacking (vs. having) a pale dorsolateral stripe; and from
L. glacialis
Greer, Allison & Cogger
and
L. stellaris
Greer, Allison & Cogger
in having a relatively unfragmented (vs. fragmented) temporal region, large chin shields abutting the infralabials (vs. separated by genials), and 22–28 (vs. 13–17) subdigital lamellae.
Description.
This description is limited to six specimens from four localities in the central Owen Stanley Mts. of
Central Province
,
Papua New Guinea
, all of which are within
100 km
of the
type
locality. All specimens I have seen from elsewhere but assigned to this species in museum collections represent other species that are typically undescribed; some of them are morphologically similar to
L. elegans
but genetically highly divergent (Slavenko
et al.
in prep.).
Rostral broad but shallow, approximately twice as wide as deep, projecting moderately onto tip of snout, its suture with frontonasal straight to shallowly concave; nasal elongate, widest anteriorly, usually entire but may have shallow dividing suture posteriorly (n = 2 of 12) or ventrally (n = 2 of 12); nasals widely separated, projecting approximately one-third of way onto dorsum of snout; nostril subcircular, centered within nasal; frontonasal large, pentagonal, extending laterally to dorsal level of nares, barely touching frontal; prefrontals moderate in size, narrowly separated, bordered below by two loreals; supraoculars four, anterior two contacting frontal; frontal kite shaped; one pair of frontoparietals in medial contact, in contact with posterior three supraoculars and in narrow contact with frontal (
Fig. 1A, C
); interparietal smaller, kite-shaped; parietal eye spot absent; parietals in contact behind interparietal, in contact anteriorly with last supraocular, last supraciliary, and uppermost postsubocular; transversely enlarged nuchal on each side, larger than the scale separating it from the upper secondary temporal.
Anterior loreal smaller than posterior, higher than long; posterior loreal longer than high (
Fig. 1B, D
); preocular longer than tall; presuboculars two (
n
= 11) or three (
n
= 1); postsuboculars five (
n
= 10) or six (
n
= 2), lowest interdigitated between penultimate and antepenultimate supralabials; lower eyelid scaly, moveable, with a clear palpebral disc approximately size of ear opening, scales of upper palpebral series 8–11, of lower palpebral series 13–14; supraciliaries eight (n = 2), nine (
n
= 7), or ten (
n
= 3), first in contact with prefrontal, last expanded medially behind posterolateral margin of fourth supraocular, none interdigitated with supraoculars; primary temporal single, interdigitated between last two supralabials; secondary temporals two, upper approximately same size as lower but more elongate and overlapping it; supralabials six (
n
= 1) or seven (
n
= 11), fourth (
n
= 1) or fifth (
n
= 11), respectively, below eye and in contact with small scales of lower eyelid; postlabials two; ear opening moderately large, with 3–6 flat lobules on anterior margin, otherwise ear margin surrounded by flat scales.
Mental single; postmental single, contacting first two infralabials; infralabials seven; four pairs of enlarged chin shields, the first two pairs in medial contact, third pair narrowly separated by single medial scale, fourth pair separated by three medial scales; a single postgenial separating fourth chin shield from seventh infralabial.
Body scales smooth, in 30 (
n
= 4), 31 (
n
= 1), or 32 (
n
= 1) longitudinal rows at midbody; paravertebral scales 52 (
n
= 3), 53 (
n
= 1), or 54 (
n
= 2); medial precloacal scales overlap lateral precloacals.
Scales on dorsal surface of fourth toe in two rows proximally, in single row beginning after last joint, 3 (
n
= 8) or 4 (
n
= 4) single dorsal scales; 22–28 smooth subdigital lamellae under fourth toe (mean = 23.2,
SD
= 0.463,
n
= 12).
In preservative, dorsal ground color brown (n = 2) or greenish brown (
n
= 2), with two rows of large, darkbrown mid-dorsal spots, sometimes connected medially, 13–16 spots in each row; additional dorsolateral row of similar spots on each side (
Fig. 2A,B
); sides with several rows of smaller dark-brown spots; many scales in dorsal and lateral ground color laterally margined in dark brown, giving the appearance of narrow dark-brown longitudinal lines on dorsum and sides (
Fig. 2B
). Dorsal surface of tail with single medial row of 6–8 large dark-brown spots proximally, changing to two rows of smaller, less-well-developed dorsolateral spots distally. Limbs and digits heavily spotted with dark brown dorsally. Ground color of head darker brown than on body, heavily marked with dark-brown along most scale margins. Ventral surfaces of body and limbs uniform white, but flecked or dusted with brown on chin, sides of neck, and under tail.
In life, BPBM 18691 and 18692 had light-brown dorsal and lateral scales with dark-brown margins, giving the appearance of stripes; two paravertebral rows of black squares (
Fig. 3A
); sides with 3–4 rows of light dashes; ground color on sides darker than on dorsum; venter white with a green sheen; palms and soles dark yellow; iris dark. The venter of BPBM 18692 was also white (no green sheen noted), but that of BPBM 18693 was yellow.
Range.
Known
with certainty only from four localities in the southern slope of the
Owen Stanley Mts.
,
Central Province
,
Papua New Guinea
(
Fig. 4
).
Elevations
for the
BMNH
specimen from
Mt. Victoria
is unknown.
The
specimens from
Fane
were obtained from
1400–1440 m
a.s.l.
;
the specimen from
Mondo
(ca.
5 km
E of Fane
) was collected at
1520 m
a.s.l.
,
and the specimen from
Mt. Obree
came from
1330–1450 m
a.s.l.
Ecological notes.
My specimens were brought in by local collectors, so I have no detailed ecological notes for them. The species is reported to be arboreal (
Greer 1974
;
Allison 1980
), but those statements likely (
Greer 1974
) or certainly (
Allison 1980
) belong to other, unnamed, though closely related, species (see Discussion). Nonetheless, the flattened body and long digits of
L. elegans
are consistent with the interpretation that the species is arboreal. The areas from which the animals at Fane and Mt. Obree were collected comprised a mix of open grasslands (likely due to human burning) and secondary forest (
Fig. 5A
), suggesting that this species is heliothermic and prefers areas open to sunshine for basking. It may well be an ecotone specialist.
Remarks.
As briefly noted in the Introduction, the large majority of specimens assigned to this species in museum collections I have seen are referable to other, mostly undescribed species that differ from true
Lobulia elegans
in a variety of scalational and color-pattern features (see Discussion for further details). However, only one of these populations currently has a binomen in synonymy with
Lobula elegans
:
Lygosoma elegantoides lobulus
was described by
Loveridge (1945)
from
2280–2440 m
a.s.l., Mt. Wilhelm,
Madang Province
,
PNG
, but it seems not to have been mentioned again in the scientific literature, although it is included in the Reptile Database as a subspecies of
L. elegans
(
Uetz
et al.
2019
)
. The
holotype
is MCZ 47067 and clearly does not represent the same species as
L. elegans
as diagnosed here. Based on information provided in
Loveridge (1945)
and photographs of the
holotype
available from MCZ (
Fig. 6
), it differs from
L. elegans
in having 34–36 midbody scale rows (vs.
30–32 in
L. elegans
), posterior loreal square or slightly higher than long (vs. longer than high in
L. elegans
), dorsal rows of dark-brown spots joined to form two mid-dorsal stripes (vs. dorsal spots distinct and not arrayed in stripes in
L. elegans
), white lateral stripe present (vs. absent in
L. elegans
), and paired dark-brown dorsal spots on the tail (vs. single row in
L. elegans
). Examining the
16 specimens
that comprise the type series of this taxon is beyond the scope of this study, but it is clear from consideration of the above-mentioned features that this taxon is not conspecific with
L. elegans
, and I hereby remove it from the synonymy of that species and recognize it as the distinct species,
L. lobulus
.
Ahl (1925)
proposed the replacement name
Lygosoma elegantoides
for Boulenger’s
Lygosoma elegans
, claiming that the name was preoccupied by both
Hinulia elegans
Gray
and
Euprepes
(
Tiliqua
)
elegans
Fischer
once
Boulenger (1887)
placed 43% of global skink diversity in the single genus
Lygosoma
. This replacement name has been little used in taxonomic works since then, with
L. elegans
being used by
Greer (1974)
,
Zweifel (1980)
,
Allison & Greer (1986)
,
Mys (1988)
, and
Greer
et al.
(2005)
, and
L. elegantoides
used by
Loveridge (1945)
and
Mittleman (1952)
. It is well beyond the scope of the present taxonomic work to wade into the wake of nomenclatural problems created by Boulenger’s reconceived
Lygosoma
, and I leave that to skink experts, who can do a more thorough job. Meanwhile I use the name
Lobulia elegans
herein simply to be consistent with all recent taxonomic literature for the species.