Oxydactyla van Kampen

ZWEIFEL, RICHARD G., 2000, Partition Of The Australopapuan Microhylid Frog Genus Sphenophryne With Descriptions Of New Species, Bulletin of the American Museum of Natural History 2000 (253), pp. 1-130 : 74

Genus Oxydactyla van Kampen

Oxydactyla van Kampen, 1913: 464 . Type species (by monotypy) Oxydactyla brevicrus van Kampen, 1913: 465 .

Sphenophryne : Parker, 1934: 152 ( Oxydactyla referred to synonymy of Sphenophryne ).

CONTENT: Five species: Oxydactyla alpestris , new species; Oxydactyla brevicrus van Kampen ; Oxydactyla coggeri , new species; Oxydactyla crassa (Zweifel) ; Oxydactyla stenodactyla , new species.

DIAGNOSIS: A genus of genyophrynine microhylid frogs (sensu Zweifel, 1971, and Burton, 1986) with the following combination of morphological characters: clavicles long and slender, reaching from scapula almost to midline of pectoral girdle; legs short, maximum TL/SVL = 0.395; tips of fingers narrow and rounded, or, if slightly flattened, not disclike and with terminal grooves lacking or only weakly indicated on fingers 2–4.

MORPHOLOGY: These are small, short-legged frogs, with a maximum known SVL of 32 mm and mature males as small as 19 mm SVL in one species. Mean TL/SVL ratios range from 0.294 to 0.366, a range that excludes almost all other species with the primitive pectoral girdle. The situation with respect to small foot size is similar: mean FT/ SVL 0.338 –0.399, with just one other species having a mean in this range. The hands are small, with the range of means HD/SVL (0.199 –0.213) falling within the lower 30% of the total range for all genyophrynine species with the primitive pectoral girdle. The fingertips show little or no trace of the expanded, flattened discs with prominent terminal grooves seen in other species with the primitive pectoral girdle. The species pair alpestris + stenodactyla has the most derived condition, with no trace of fleshy expansion or grooving (fig. 49) and with the underlying terminal phalanges having slightly constrict- ed tips much narrower than the base of the bone (fig. 71A, B). In other species of Oxydactyla the tips may be slightly flattened but with no more than a faint terminal groove on fingers 2–4, and the terminal phalanges (where known) are bluntly T-shaped with the tip not or scarcely wider than the base (fig. 71C, D). The toe tips of alpestris and stenodactyla resemble those of the fingers externally, although the terminal phalanges have slightly more of a T shape. Toe tips in the other Oxydactyla are less extremely modified from the common slightly expanded disc with T-shaped phalanges. The tympanic annulus is not well defined externally, but the ear is not notably reduced in size. Mean eye size is small to moderate (EY/SVL 0.093 – 0.117). These frogs have the morphology commonly associated with cryptic, terrestrial habits, which fits well with what is known of their ecology. See table 10 for body proportions of the species and table 11 for regression statistics.

DISTRIBUTION: The genus is montane and confined to high elevations, with records ranging from 1800 to 4000 m. One species is in the central ranges of Irian Jaya, three in the highlands of Papua New Guinea, and one far to the southeast on the eastern tail of Papua New Guinea.