SPHENOPHRYNE - American Museum of Natural History

2000 ZWEIFEL: PARTITION OF SPHENOPHRYNE
83
are: SVL 28.6, HW 10.7, TL 9.6, EY 3.0,
EN 2.2, IN, 2.9, HD 5.5, FT 10.6, FD of 0.6,
TD 0.8; TL/SVL O.336, HW/SVL 0.374,
HD/SVL 0.210, FT/SVL 0.399, EY/SVL
0.105, EN/SVL 0.077, IN/SVL 0.107, EN/IN
0.722, FD/SVL 0.021, TD/SVL 0.029.
This is a small (up to 30 mm), chunky,
short-legged species. Snout bluntly pointed
as seen from above, rounded and projecting
slightly in profile; nostrils lateral, just visible
from above, slightly closer to snout tip than
to eye but in lateral view nearly terminal;
loreal region flat, moderately steeply sloping,
canthus rostralis abrupt but not sharp. Eyes
relatively small (EY/SVL 0.109), eyelid
width equals about 60% of interorbital distance.
Tympanum relatively large (75% of
EY) but scarcely distinct externally. Relative
lengths of fingers 4 3 5 2 1, first
more than half length of second; tips not
disclike, rounded, equal to or slightly broader
than penultimate phalanges, terminal groove
not (or but faintly) present; subarticular and
metacarpal elevations low, rounded. Toes unwebbed,
relative lengths 4 3 5 2
1, tips flattened and broadened into small but
distinct discs with terminal grooves; subarticular
and inner metatarsal elevations low,
rounded; no outer metatarsal tubercle. A
weak, diagonal postocular fold. Back with
numerous short skin folds and indistinct rugosities;
a -shaped pair of folds in the
scapular region; hind legs somewhat rugose.
Ventral surfaces smooth.
COLOR AND PATTERN: In preservative, the
dorsum is light brown with indistinct, random,
tiny darker spots and some larger spots
on the flanks. Lumbar eyespots are more or
less evident. The loreal region is slightly
duskier than the back. A narrow dark band
passes from the tip of the snout through the
nostril to the eye and resumes at the posterior
corner of the eye, following the postocular
fold across the upper edge of the tympanum.
This band may terminate anterior to the arm
or may continue as a series of spots or as a
stripe for a short distance above and past the
arm. The venter is pale with relatively large,
irregular dark spots, larger on the chin than
on the abdomen. The anterior and posterior
surfaces of the thighs have dark, splotchy
markings, and the posterior surface has an
ill-defined, dark triangular seat patch. The
undersides of the thighs are pale with obscure
dusky markings, whereas the shanks
are marked more like the abdomen. The
palms are pale with dark markings, the soles
the reverse.
Brass (1956: 130) called these frogs ‘‘reddish
brown’’; I have not examined living individuals.
VARIATION IN SIZE AND PROPORTIONS:
Nothing can be said of geographic variation,
as the few specimens all come from the same
mountain. The smallest of the 12 specimens
(SVL 23.7 mm) is at or close to maturity, as
it has ova 1 mm in diameter; I cannot be
sure of the sex of the largest specimen (SVL
30.1 mm). Proportions are summarized in table
10, regression data are presented in table
11.
ILLUSTRATIONS: Hand and foot, fig. 53E.
CALL: Brass (1956: 130) characterized the
sound of a chorus of these frogs as ‘‘like concerted
cackling in a distant fowl-yard.’’
James Menzies recorded three individuals
at Betamin, Mt. Dayman, 2050 m, in July
1984. The note is a soft ‘‘coo’’ lasting about
0.35 sec (0.26–0.41, N 9; see fig. 77C)
and repeated about every 16 sec (13–18, N
5 intervals). I have recordings of four
notes of one frog, three of another, and two
of a third. The unpulsed note is finely tuned
in all instances and maintained at a frequency
of 900 Hz. One individual consistently initiated
each of four notes with a brief (0.05
sec) segment at 1050 Hz before dropping to
900 Hz. This was not true of the other frogs.
Menzies (personal commun.) recorded one
frog at between noon and 1300 hours, the
others at about 2100 hours. One frog was
found calling from the ground beneath a leaf,
whereas the others were deeper in the substratum
and were not captured. Menzies recorded
the body temperature of a calling frog
as 17C where the ground was 13.2C.
COMPARISONS WITH OTHER SPECIES: No
other Oxydactyla is known from the area in
which crassa occurs. Austrochaperina brevipes,
a species of similar size and habitus,
occupies much the same habitat in the Owen
Stanley Mountains to the northwest. If questionable
specimens are captured in an intermediate
region and vocalizations are not
known, such specimens should be diagnosed
especially on the basis of the nature of the