Austrochaperina yelaensis, 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 : 54-56

Austrochaperina yelaensis , new species

HOLOTYPE: AMNH A135406 , collected by R. F. Peterson on the Fifth Archbold Expedition between October 12 and 20, 1956, at an elevation of 700 m on the south slopes of Mt. Rossel , Yela (= Rossel) Island, Milne Bay Province, Papua New Guinea.

PARATYPES: There are no paratypes.

ETYMOLOGY: The Latin adjectival suffix - ensis (origin) reflects the provenance of the holotype, the name of which has been changed from Rossel Island to Yela Island.

DIAGNOSIS: A small Austrochaperina — SVL 20.5 mm in the single specimen, a female at or close to adulthood—with moderately well-developed digital discs, an obscurely mottled dorsal color pattern, small pale spots prominent on the face and side of body, and mottled abdomen.

DESCRIPTION OF HOLOTYPE: A female, at or close to maturity (ova 1.5 mm in diameter), with the following measurements and proportions: SVL 20.5, HW 7.9, TL 9.3, EY 2.8, EN 1.6, IN 2.3, HD 4.2, FT 9.3, disc of third finger 0.6 (penultimate phalanx 0.4), disc of fourth toe 0.8 (0.4); HW/SVL 0.385, TL/ SVL 0.454, EY/SVL 0.127, EN/SVL 0.078, IN/SVL 0.112, EN/IN 0.696, HD/SVL 0.205, FT/SVL 0.454, FD/SVL 0.029, TD/ SVL 0.039.

Head scarcely narrower than body, snout obtusely rounded, barely projecting in profile; loreal region sloping and flat, canthus rostralis rounded; nostrils barely visible from above, nostril closer to tip of snout than to eye. Eyes relatively large, visible from beneath, interorbital distance about 80% of an eyelid width; tympanum hidden. Relative lengths of fingers 3> 4> 2> 1, first finger well developed, about half length of second, all fingers with small, grooved terminal discs; subarticular and inner metacarpal elevations low and rounded (fig. 57A). Toes unwebbed, relative lengths 4> 3> 5> 2> 1, all with grooved terminal discs, those of third and fourth toes about twice width of penultimate phalanges; subarticular and inner metatarsal elevations low but discrete, no outer metatarsal elevation (fig. 57A). Skin smooth above and below, a faint trace of a postocular-supratympanic fold.

The dorsum is brown and faintly mottled. Small white spots are prominent atop the snout, on the upper lips and sides of the face through the tympanic region, and along the side of the body. The upper surfaces of the hands, arms, and front legs and hind legs are similarly spotted. The throat and chest are brown with white spots, the abdomen and undersides of hind legs mottled. The groin and anterior surface of the thigh are brown with irregular, small light marks; the posterior surface is similar but with slightly larger markings.

VARIATION IN TYPE SERIES: There is only the single specimen, so the extent and nature of variation are unknown. That the specimen is mature at less than 21 mm SVL indicates that this is one of the smallest species of Austrochaperina .

ILLUSTRATIONS: Hand and foot, fig. 57A.

CALL: The vocalizations, if any, are unknown.

COMPARISONS WITH OTHER SPECIES: Austrochaperina yelaensis is most similar to anoth- er insular species, A. novaebritanniae , found 700 km distant on a geologically unrelated island, New Britain. The single specimen of yelaensis has the middorsal region unspotted (spotted in novaebritanniae ), the abdomen mottled rather than spotted, and slightly longer hind legs than in any of the series of 29 adult novaebritanniae (TL/SVL 0.454 vs. 0.452). No other species of Austrochaperina is known from Yela Island. There is also similarity in size, proportions, and color pattern between yelaensis and mehelyi , a species slightly more remote geographically from yelaensis but on the New Guinea mainland. Slightly larger finger discs, longer EN and smaller IN spans may also characterize yelaensis , although confirmation will require more specimens of that species.

HABITAT AND HABITS: No information particular to the specimen is available. The surroundings of the camp included a mountain ridge with ‘‘mossy, wind-clipped forest’’ and ‘‘an abundance of woody undergrowth’’ (Brass, 1959: 57).

DISTRIBUTION: Known only from the type locality (fig. 30).

Genus Liophryne Boulenger

Liophryne Boulenger, 1897: 11 . Type species not specified between the two new species Boulenger assigned to the new genus, L. rhododactyla and L. brevipes . Parker (1934: 152) stated ‘‘ Type species Liophryne rhododactyla ,’’ which constitutes a valid subsequent designation (International Commission on Zoological Nomenclature, 1985: Art. 69(a)(iv)).

Sphenophryne : Parker, 1934: 152.

CONTENT: Six species: Liophryne allisoni , new species; Liophryne dentata (Tyler and Menzies) ; Liophryne similis , new species; Liophryne rhododactyla Boulenger ; Liophryne rubra , new species; Liophryne schlaginhaufeni (Wandolleck) .

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; fingers and especially toes with relatively prominent (rather than low), rounded subarticular elevations; tips of fingers and toes expanded into small discs with terminal grooves, those of fingers narrower than of toes; span of Tshaped tip of terminal phalanx of third finger not or scarcely wider than base of phalanx; legs long, minimum mean TL/SVL (0.488) and minimum mean FT/SVL (0.488) greater than means of any other genyophrynine species with the primitive pectoral girdle.

MORPHOLOGY: The species of Liophryne present a spectrum of sizes, from adult males of allisoni as small as 20 mm SVL to a female record size of 60 mm in rhododactyla , the largest size attained by any genyophrynine microhylid. Species of Liophryne are rather broad-headed frogs, including the two highest and six of the nine highest mean HW/SVL ratios of all genyophrynines considered herein. The vast majority of genyophrynine frogs show scarcely any development of subarticular elevations, being usually low, rounded ones at best. The species I assign to Liophryne agree in having discrete subarticular structures and also share, on the average, the relatively longest legs (as measured by the TL/SVL and FT/SVL ratios) of any of the species with the primitive pectoral girdle. The finger and toe discs are small, neither reduced or absent as in Oxydactyla nor enlarged as in Sphenophryne and many Austrochaperina . In three species, rhododactyla (and probably also similis ), dentata , and schlaginhaufeni , the medial plate of the vomer is large and the lateral arm relatively thick (fig. 65F–H), possibly an indication of close relationship, though the vomer of allisoni is somewhat more delicately formed (fig. 65E). Five species, excepting allisoni , have a relatively large and distinct ear. For body proportions, see table 6; regression statistics are in table 7.

DISTRIBUTION: Found throughout much of New Guinea, from near sea level to 2700 m and from Timeka in western Irian Jaya to Milne Bay at the eastern tip of Papua New Guinea, but not known from any satellite islands.

REMARKS: Advertisement calls are diverse—single and unpulsed in rhododactyla , trains of unpulsed notes in allisoni and similis , a train of pulsed notes in schlaginhaufeni , and a long variable train of pulsed notes in dentata . The call of one species, rubra , is unknown.