SPHENOPHRYNE - American Museum of Natural History

2000 ZWEIFEL: PARTITION OF SPHENOPHRYNE
93
NOMINA DUBIA
Microbatrachus Roux 1910
Microbatrachus Roux, 1910: 228. Type species
(by monotypy) Microbatrachus pusillus Roux
1910: 228.
Sphenophryne: Tyler, 1978: 459 (Microbatrachus
considered a junior synonym of Sphenophryne).
Microbatrachus pusillus Roux
Microbatrachus pusillus Roux, 1910: 228 (type
locality, ‘‘Pobdjetur, Terangan,’’ Aru Islands,
Indonesia; holotype, NMBA 2732, collected
Feb. 6, 1908, by H. Merton and J. Roux). Van
Kampen, 1923: 121. Nieden, 1926: 50. Parker,
1934: 179. Forcart, 1946: 135.
Sphenophryne pusilla: Tyler, 1978: 459.
TYPE MATERIAL: The type specimen is a
juvenile 7 mm SVL that ‘‘has been extensively
dissected . . . and very badly damaged
in the process’’ (Tyler, 1978: 457).
DIAGNOSIS: The condition and immaturity
of the type specimen allow diagnosis of neither
the species nor of the genus of which it
is the type species.
MORPHOLOGY: The following description is
from van Kampen (1923: 121) and evidently
is his paraphrase of the original description,
as he did not examine the type specimen:
‘‘Tongue large, subtriangular, about half free
behind. Head nearly as long as broad; snout
broadly truncated, as long as the eye; no canthus
rostralis; nostril in the middle between
the orbit and the tip of the snout; interorbital
space 1 times the width of the upper eyelid;
tympanum hidden. Fingers obtuse; second to
fifth toe with very feebly dilated tips; fingers
very short, first shorter than second, which is
shorter than fifth; no subarticular or metatarsal
tubercles; the heel reaches the posterior
border of the eye.’’
‘‘Skin smooth.’’
Roux (1910: 228) stated: ‘‘Sternal apparatus
cartilaginous, extremely simple. Sternum
a narrow plate. Coracoid and procoracoid
present. No clavicle, no omosternum.’’
Tyler (1978) noted that as tiny a bone as the
clavicle of specimen of this size might easily
have been overlooked or lost in dissection.
Except for the peculiar Genyophryne, no
genyophrynine frog possesses a procoracoid
but lacks the clavicle.
COLOR AND PATTERN: ‘‘Upper parts brown,
darker on the head and the anterior part of
the back; fore limbs greyish white, hind
limbs yellowish brown; lower parts yellowish
white, the throat a little darker, with small
lighter dots. Length 7 mm’’ (van Kampen,
1923: 121–122).
ILLUSTRATIONS: Roux (1910: pl. 14) illustrated
the body in dorsal aspect (fig. 6), open
mouth (fig. 6a), and pectoral girdle (fig. 6b).
HABITAT AND HABITS: ‘‘We took this tiny
amphibian from wet soil at the edge of a
stream’’ (Roux, 1910: 229).
DISTRIBUTION: This species is known only
from the type locality (fig. 48).
REMARKS: The systematic position of Microbatrachus
pusillus has elicited comments
from most authors dealing with the species:
‘‘Perhaps a young Sphenophryne or Oreophryne
sp.’’ (van Kampen, 1923: 122); ‘‘almost
certainly the young of an Oreophryne’’
(Dunn, 1928: 4); ‘‘This genus may . . . prove
to have been founded on an immature Oreophryne
or Sphenophryne, more probably
the latter’’ (Parker, 1934: 179). Only Tyler
(1978), who placed Microbatrachus in the
synonymy of Sphenophryne, has gone into
the matter in detail, including examination of
the type specimen. With allowance for the
poor condition of the specimen, Tyler made
a strong case for eliminating Cophixalus and
Oreophryne from consideration, leaving
Sphenophryne as the most likely candidate.
The possibility that Microbatrachus represents
a valid genus was given little credence
by these authors.
Tyler’s (1978) allocation of Microbatrachus
as a junior synonym of Sphenophryne
was reasonable at the time, but with Sphenophryne
(sensu Parker, 1934) now sundered
into four genera, the status of Microbatrachus
is more obscure than ever. In nomenclatural
priority, Microbatrachus (1910)
stands ahead of Austrochaperina (1912) and
Oxydactyla (1913). The last is a genus of
montane frogs most unlikely to be found on
the Aru Islands. Austrochaperina, however,
might well occur there, and I have commented
elsewhere (Zweifel, 1985b: 285) that
pusillus may be a senior synonym of A. adelphe
(Australian) or A. gracilipes (Australian
and Papuan), either of which lowland species
may occur on the Aru Islands.
My present view is that because of the