SPHENOPHRYNE - American Museum of Natural History

2000 ZWEIFEL: PARTITION OF SPHENOPHRYNE
81
than penultimate phalanges, only third with
faint terminal groove (fig. 53D); subarticular
and metacarpal elevations low, rounded, inconspicuous.
Toes unwebbed, relative
lengths 4 3 5 2 1, first short, its
tip barely reaching to subarticular elevation
of second; tips of second to fourth flattened
with terminal grooves but little or no wider
than penultimate phalanges, first and fifth
less flattened, fifth sometimes weakly
grooved (fig. 53D); subarticular elevations
low, rounded, inner metatarsal elevation low,
elongate, rounded. Dorsal region with many
small, inconspicuous tubercles but no folds;
a weak postocular-supratympanic fold curving
downward behind ear; venter smooth.
The color in preservative is various shades
of brown. The facial region is purple-brown,
being more concentrated in the canthal area.
The area behind the eye is dark, bordered
above on a diagonal line directed to the insertion
of the arm. A dark postocular streak
extends posterior from the eye as a dark band
passing above the foreleg and then discontinuously
to the groin. The region beneath this
band is vaguely mottled brown, paler than
the postocular streak. A pale vertebral hairline
passes from the snout to just anterior to
the cloaca, where it divides and runs along
the rear of the thigh and weakly onto the
shank. On the back, a narrow streak of dark
brown borders the hairline and is in turn bordered
by a wider swath of lighter brown,
slightly darker than the side of the body below
the dark dorsolateral streak. A prominent
black spot lies just anterior to the cloaca. The
upper sides of the legs are brown with darker
spotting, and the back of the thigh below the
light line is indistinctly mottled dark and
light brown. The chin and chest bear dense,
even melanic stippling, which gives way
abruptly on the abdomen to a sparser stipple,
often with scattered dark spots.
VARIATION IN TYPE SERIES: See table 10 for
variation in proportions and table 11 for regression
data. The largest specimen is a female,
28.2 mm SVL. The size of females at
maturity is about 20–21 mm, as three frogs
19.3–20.6 mm appear to be immature,
whereas two at 20.6 mm are gravid. The
range in size of mature males (vocal slits present)
is 19.0–26.7 mm SVL.
The back may be unicolor, may have small
dark spots, and may have, as does the holotype,
a light, midvertebral hairline. Nearly
half the specimens tabulated (15 of 38) show
at least a trace of the vertebral hairline,
which is not always as well developed as described
for the holotype.
ILLUSTRATIONS: 3rd finger terminal phalanx,
fig. 71D; premaxilla, fig. 63C; sacral region,
fig. 72C; vomer, fig. 65C; skull, fig. 67B; hand
and foot, fig. 53D.
CALL: James I. Menzies recorded this species
at an elevation of 2300 m at Kaironk
where the frog (UPNG 837) called from the
leaf litter at noon. The two recorded calls
each have 11 pure-toned, unpulsed musical
notes given over about 2.3 sec at a rate 4.4–
4.5 notes per second (fig. 78B). Notes are
0.04–0.05 sec long and are slightly frequency
modulated, dropping about 50 Hz from an
initial 900 Hz. Menzies and Tyler (1977)
published an audiospectrogram of part of one
of these calls in connection with a discussion
of vocalization of burrowing microhylids.
COMPARISONS WITH OTHER SPECIES: Oxydactyla
coggeri is distinguished from the
other species of Oxydactyla known in the
same general area of New Guinea—alpestris
and stenodactyla—in possessing toe discs.
Similar in morphology, although widely separated
geographically, coggeri and crassa
differ in advertisement calls and sufficiently
in certain proportions to permit correct assignment
of a large majority of specimens in
a mixed sample without reference to geography
(fig. 40).
HABITAT AND HABITS: Dr. Harold Cogger
(personal commun.) reported finding this
species under logs at 2200 m just inside primary
rainforest (above grassland).
DISTRIBUTION: Oxydactyla coggeri is
known only from two regions. All but one
specimen came from the Kaironk Valley–
Schrader Mountains area of Madang Province,
Papua New Guinea, at the northern
edge of the highlands region. A single specimen
is from near Mendi, Southern Highlands
Province, 120 km to the southwest.
Possibly the species may have an extensive
range in Enga Province, west of the Schrader
Range and north of Mendi, where there has
been little collecting (fig. 41). See Holotype
and Paratypes for localities and specimens
examined.