Austrochaperina adamantina, ZWEIFEL, 2000

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 : 11-12

Austrochaperina adamantina , new species Figure 4

HOLOTYPE: AMNH A78185 , collected by

Jared Diamond on July 14, 1966, in West Sepik Province, Papua New Guinea, on Mount Nibo, 9 km N, 15.5 km E of Lumi, at an elevation between 700 and 1550 m.

PARATYPES: There are no paratypes.

ETYMOLOGY: The specific name (Latin, ‘‘like a diamond’’) refers to Jared Diamond, the collector of this and a great many other valuable herpetological specimens from Papua New Guinea.

DIAGNOSIS: A species of moderate size (28 mm SVL, one specimen), lacking toe webbing, with the following diagnostic combination of proportions: eyes large (EY/SVL 0.125), leg length moderate (TL/SVL 0.434), narrow head (HW/SVL 0.338), narrow internarial span (IN/SVL 0.098), and moderately large finger discs (3rd finger disc/SVL 0.041). Eleven New Guinean Austrochaperina are eliminated on criteria of size and/or toe webbing alone, and the remaining eight are eliminated on proportions. Differences from the most similar species, A. macrorhyncha , are discussed under Comparisons.

DESCRIPTION OF HOLOTYPE: Adult female (gravid) with the following measurements and proportions: SVL 28.1, HW 9.5, TL 12.2, EY 3.5, EN 2.05, IN 2.75, HD 6.3, FT 12.5, third finger disc 1.15 (penultimate phalanx 0.55), fourth toe disc 1.2 (0.65), TY 1.4; HW/SVL 0.338, TL/SVL 0.434, EY/SVL 0.125, EN/SVL 0.073, IN/SVL 0.098, HD/ SVL 0.224, FT/SVL 0.445, third finger disc/ SVL 0.041, fourth toe disc/SVL 0.043.

Head narrow, snout truncate seen from above, slightly rounded in profile; canthus rostralis rounded but moderately distinct, loreal region nearly vertical, slightly concave, nares not visible from above; eyes (corneal outline) visible from below; eyelid about as wide as interorbital space; tympanic ring scarcely evident externally. Relative lengths of fingers 3> 4> 2> 1, all well developed with broad, grooved discs, that of third finger about 2X penultimate phalanx; subarticular and inner metacarpal elevations low, round- ed, scarcely evident (fig. 55E). Toes unwebbed, relative lengths 4> 3> 5> 2> 1, terminal discs well developed, that of fourth toe slightly broader than that of third finger; subarticular elevations scarcely evident (fig. 55E). Skin smooth dorsally and ventrally except for very slight wartiness on the lower back; a weak, diagonal postocular-supratympanic fold.

Dorsum tan with indistinct darker mottling; side of face and upper lip from just below nostril to tympanic fold abruptly paler than top of snout. Undersides all pale with faint darker mottling, slightly darker on throat and hind legs; posterior of thighs pale with mottling darker than undersides but pal- er than dorsum and top of thighs.

VARIATION IN TYPE SERIES: Only the single specimen is known.

ILLUSTRATIONS: Hands and feet, fig. 55E.

CALL: The call is unknown.

COMPARISONS WITH OTHER SPECIES: At present only two other species of Austrochaperina are known from the Torricelli Mountains: A. basipalmata and A. aquilonia . The basally webbed toes should immediately distinguish basipalmata from adamantina . Other characters differentiating adamantina from basipalmata include smaller size (gravid at 28 mm SVL vs. minimum size at maturity of 33 mm), narrower head (HW/SVL 0.338 vs. minimum of 0.343), and larger eyes (EY/SVL 0.125 vs. maximum of 0.112). See the account of A. aquilonia for comparison with that species. The relatively small size of adamantina distinguishes it from oth- er species with similar proportions.

HABITAT AND HABITS: Nothing is on record.

DISTRIBUTION: Known only from the type locality in the Torricelli Mountains on the north coast of Papua New Guinea (fig. 7).

Figures

Fig. 4. Holotype of Austrochaperina adamantina, AMNH A78185, SVL 28.1 mm.