Oxydactyla alpestris, 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 : 75-80

Oxydactyla alpestris , new species Figure 39

Sphenophryne brevicrus : Zweifel, 1956: 10 (part, specimens from Mt. Hagen). Tyler, 1963: 18 (part?).

HOLOTYPE: AMNH A76584 (field no. Fred Parker 293), collected on April 17, 1965, by Fred Parker at Gomgale Pass, elevation about 2400 m, approximately 17 km south and 15 km west of Kundiawa, Simbu Province, Papua New Guinea.

PARATYPES: All from Papua New Guinea. Eastern Highlands Prov.: AMNH A76585 , MCZ A59653–59663 , collected by Fred Parker, Oct. 3, 1965, at Daulo Pass , 2480 m, 5 km N, 18 km W Goroka ; AMNH A66240 , A66335 , collected on the Sixth Archbold Expedition, Aug. 7–9, 1959, at Kotuni, S slope Mt. Otto , 2100–2440 m ; MCZ A59616 , collected by Fred Parker, Feb. 21, 1966, at Kotuni, 1800 m. Simbu Prov.: MCZ A59667– 59673 , collected by Fred Parker, Apr. 17, 1965, at Gomgale Pass , 2400 m, 17 km S, 15 km W Kundiawa ; AMNH A76582 , A76583 , and MCZ A59626–59647 , collected by Fred Parker, Mar. 29, 1965, at Sikuri Pass , 4 km S, 13 km E Kundiawa ; MCZ A68349 , collected by Fred Parker, June 4, 1967, at Tuna Pass , 2600 m ; MCZ A59617–59625 , 64294 , 64295 , collected by Fred Parker, Nov. 30, 1965, and Aug. 21, 1967, at Dumun , 2300–2400 m, 6 km S, 8 km E Kundiawa ; MCZ A59649 –59652 , collected by Fred Parker, Jan. 1, 1965, at Masul , 8 km S, 10 km E Kundiawa ; MCZ A59648 , collected by Fred Parker, Sept. 26, 1965, at Mintima , 4 km N, 6 km W Kundiawa ; MCZ A59674– 59681 , collected by Fred Parker, Nov. 15, 1965, at Derim, Kwi Valley ; MCZ A59682– 59695 , collected by Fred Parker, Nov. 26, 1965, at Agakamatasa ; MCZ A59664 – 59666 , collected by Fred Parker, July 28, 1965, on the southern slope of Mt. Kerigomna , 2590–2890 m ; MCZ A80001 , 80002 , collected by Fred Parker, Nov. 13, l965, on the southwest slope of Mt. Kerigomna, 2590 m. Western Highlands Prov.: AMNH A65304–65308 , collected on the SpaldingPeterson Expedition, Aug. 10, 1959, on the Wahgi Dividing Range near Nondugl , 2440 m ; AMNH A65281–65301 , 65303 , collected on the Spalding – Peterson Expedition, Aug. 6, 1959, on Mt. Pollam, Wahgi Dividing Range near Nondugl , 2490 and 2740 m ; AMNH A56272 , A58171–58174 , collected by E. T. Gilliard in 1950 or 1952 on Mt. Hagen , 2440 m ; BPBM 3008 , 3014 , 3305 , collected by J. Sedlacek, May 24, 1963, and MCZ A64088–64097 , collected by Fred Parker, Mar. 24, 1967, at Tomba , 2450 m, 3 km N, 23 km W Mt. Hagen town .

ETYMOLOGY: The specific name, a Latin adjective meaning ‘‘living in high mountains,’’ is appropriate for this species.

DIAGNOSIS: Differs from other Oxydactyla except O. stenodactyla in that the toe tips as well as fingertips are rounded, not expanded or flattened, and lack terminal grooves. The eyes of alpestris are relatively larger and the legs relatively longer than those of stenodactyla (see Comparisons).

DESCRIPTION OF HOLOTYPE: Adult female (ova up to 2 mm in diameter) with the following measurements and proportions: SVL 22.7, HW 8.6, TL 8.2, EY 2.6, EN 1.4, IN 2.2, TY, 1.1, HD 4.8, FT 8.8; TL/SVL 0.361, HW/SVL 0.379, EY/SVL 0.114, EN/SVL 0.062, EN/IN 0.636, IN/SVL 0.097, HD/ SVL 0.211, FT/SVL 0.388.

A stout, short-legged frog, body wider than head; snout rounded in dorsal aspect, slightly more flattened in profile and scarcely projecting beyond the mouth; nostrils easily visible from above, closer to end of snout than to eye, appearing nearly terminal in profile; canthus rostralis rounded, loreal region sloping, flat; eyes relatively large, corneal margin barely visible from beneath, interorbital space about 1.5X width of an upper eyelid; tympanic annulus indistinct, tympanum separated from posterior corner of eye by about its own diameter. Relative lengths of fingers 3> 2 = 4> 1, first well developed, more than half length of second, tips narrow, rounded, not flattened, no trace of terminal groove (fig. 53B); subarticular elevations virtually nonexistent, inner and middle metacarpal elevations indistinct, low and rounded. Toes unwebbed, relative lengths 4> 3> 5> 2> 1, first small, less than half length of second, tips and subarticular elevations as on hands, inner metatarsal elevation small, low, rounded, no outer elevation. Body surfaces smooth dorsally and ventrally; no skin folds or wartiness.

The dorsal ground color is medium brown. The side of the head and the eyelids are dark- er, almost black, with a few light flecks on the upper lips. A dark brown streak begins behind the eye, broadens as it passes above and behind the tympanum, and fades into the ground color as it extends diagonally down the midflank region. The upper edge of this streak is clearly defined only anteriorly. The middorsal region shows only a few obscure hints of darker markings. The upper surfaces of the limbs are similar but with markings more obvious, especially on the arms. The immediate region of the cloacal opening is pale, surrounded by a black ring. The anterior surfaces of the thighs are brown with indistinct lighter spots; the posterior surfaces have a pale tan ground color mostly obscured by darker pigment in no definite pattern. The ground color of the undersides is pale tan. The border of the lower jaw is dark with a few light spots. Irregular clumps of dark pigment on the throat and chest are less dense on the abdomen but again dominant on the undersides of the hind legs. The sole is dark with a few light flecks.

VARIATION IN TYPE SERIES: The largest specimens are two females from Tomba measuring 27.8 mm SVL. The largest males are two from Agakamatasa measuring 26.6 and 26.9 mm. Both males and females are unusually large in comparison with frogs from other samples, where the largest male is 24.7 mm and females rarely attain 26 mm. Females mature at about 20 mm. See table 10 for variation in body proportions and table 11 for regression data.

ILLUSTRATIONS: 3rd finger terminal phalanx, fig. 71B; premaxilla, fig. 63B; sacral region, fig. 72B; vomer, fig. 65B; hand and foot, fig. 53B.

CALL: The call has not been described.

COMPARISONS WITH OTHER SPECIES: The species with which O. alpestris is most likely to be confused are O. coggeri and O. stenodactyla . Known localities for alpestris are remote from those for coggeri , but if the species should be found together (for example, in eastern Enga Province), the presence of grooved, disclike toe tips in coggeri provides adequate distinction.

The habitat of stenodactyla appears to be generally at higher elevations than that of alpestris , but the two species evidently occur together on the Sepik-Wahgi Dividing Range. Although there is overlap between the two species in ranges of all the standard ratios (table 10), the means are well separat- ed, and combining two ratios (TL/SVL and EY/SVL) achieves a nearly complete division (fig. 46). Specimens of stenodactyla from the sympatric sample fall within the area of the stenodactyla sample in figure 22.

HABITAT AND HABITS: Tyler (1963), in reporting studies made on the Sepik-Wahgi Dividing Range, published the only information that may pertain to alpestris (as Sphenophryne brevicrus ). Both alpestris and stenodactyla occur in the region where Tyler worked, but judged from the range of elevations cited (specimens taken on saturated ground beneath moss at 1800–2400 m), his observations on habitat, reproduction (egg-brooding observed, but adult sex not noted), and food habits (one found eating an earthworm) most likely apply to alpestris .

DISTRIBUTION: Oxydactyla alpestris occurs at elevations of 1800–2740 m in Western Highlands, Simbu, and Eastern Highlands Provinces of Papua New Guinea (fig. 41). The known range spans 160 km from Mt. Hagen east to Mt. Otto, although large areas—most notably the entire Kubor Range— are as yet unrepresented by specimens. See Holotype and Paratypes for localities and specimens examined.

Oxydactyla brevicrus van Kampen Oxydactyla brevicrus van Kampen, 1913: 465

(type localities ‘‘Hellwig-Gebirge, ± 2500 m

.... [and] Wichmann-Gebirge, ± 3000 m.’’;

lectotype ZMA 5714 from the Hellwig Mountains designated by Daan and Hillenius [1966],

collected by H. A. Lorentz in October 1909).

Sphenophryne brevicrus : Parker, 1934: 158 (first use of combination). Zweifel, 1956: 10 (part).

TYPE LOCALITIES: The type localities are in the central mountainous region of Irian Jaya, south-southeast of Peak Trikora (Mt. Wilhelmena) at about 4°20′35̎S, 138°20′35̎E (Wichmann) and 4°30′10̎S, 138°40′10̎E (Hellwig). The choice of the lectotype was dictated by its being the individual illustrated by van Kampen as well as being the only adult in the type series.

DIAGNOSIS: Differs from its congeners in that the tips of the toes are somewhat flattened rather than narrow and rounded, but not disclike with terminal grooves.

MORPHOLOGY: A rather chunky bodied, relatively short-legged frog. Head slightly narrower than body. Snout rounded as seen from above and in profile; nostrils readily visible from above, slightly closer to tip of snout than to eyes; loreal region a gentle slope, almost flat; canthus rostralis rounded, not distinct. Eyes large, corneal outline just visible from beneath, eyelid about 80% of interorbital span. Tympanum almost completely hidden. Relative lengths of fingers, 3> 2 = 4> 1 (or 4> 2), first more than one-half length of second; tips rounded, not disclike, third finger with possibly a trace of a terminal groove (fig. 53C); subarticular elevations very low, rounded. Toes unwebbed, relative lengths 4> 3> 5> 2> 1, tips somewhat flattened but not distinctly disclike, not expanded, no distinct terminal grooves (fig. 53C); subarticular elevations scarcely evident, inner metatarsal elevation elongate, low and rounded. A weak postorbital-supratympanic fold, skin otherwise smooth dorsally and ventrally.

COLOR AND PATTERN: The dorsal ground color in preservative is tan. A narrow dark brown canthal line continues postorbitally, broadening on the flank, but there it is almost lost in an abundance of irregular brown spots. Such spots are present middorsally, on the flanks, the head and facial region, and legs. They are largest on the back and legs. The posterior of the thigh bears small, irregular dark spots, some of which run together, on a pale tan background. The lower jaw is edged with a band of brown, irregular on its inner margin, whereas the rest of the chin is pale with a few small darker spots. The chest and abdomen are pale with irregular, indistinct spotting, not greatly different from the chin.

The preceding account of morphology and color pattern describes the best preserved specimen (MZB 448). Several of the remaining specimens available to me are somewhat desiccated, so the character of the digital tips cannot adequately be assessed. However, one specimen in reasonably good condition has the digits as described above, and the original description stressed the lack of adhesive discs. The described specimen is the most boldly marked one examined. The others are more like the illustration in the original description (van Kampen, 1913, pl. 11, fig. 8), with dark facial region and flanks, and the dorsum only obscurely marked.

VARIATION IN SIZE AND PROPORTIONS: Females evidently mature at about 24–25 mm SV, and the largest specimen is a female of 27.2 mm. A male measures 24.2 mm; I have not determined the size at maturity. See table 10 for statistics on proportions and table 11 for regression data.

ILLUSTRATIONS: 3rd finger terminal phalanx, fig. 71C; hand and foot, fig. 53C.

CALL: The call is unknown.

COMPARISONS WITH OTHER SPECIES: Oxydactyla brevicrus has been confused with high montane species of Papua New Guinea that have either less ( alpestris , stenodactyla ) or greater ( coggeri ) development of toe discs. The only somewhat similar species known in the mountains of Irian Jaya is Austrochaperina kosarek , which has well-developed toe discs and longer legs (TL/SVL = 0.409).

HABITAT AND HABITS: There is nothing specific published concerning this species. Archbold et al. (1942: 258–266) described in detail the region in which the AMNH specimens were collected, an area of steep mountain slopes and valleys, with tall forests where not disrupted by native agricultural practices.

DISTRIBUTION: Oxydactyla brevicrus is known from elevations of 2200–3000 m in a restricted region of the central dividing range of Irian Jaya (fig. 10). Published records for brevicrus 600 km or more to the east in Papua New Guinea are based on other species (see O. coggeri , O. alpestris , and O. stenodactyla ).

LOCALITY RECORDS AND SPECIMENS EXAMINED: IRIAN JAYA: Hellwig Mtns. , 2500 m ( ZMA 5714 , lectotype) ; Wichmann Mtns. , 3000 m ( ZMA 5715 , 5716 , lectoparatypes) ; 9 km NE Lake Habbema , 2800 m ( AMNH A43696 , A43698 ) ; Bele River , 2200 m, 18 km N Lake Habbema ( AMNH A43761– 43763 ) ; Doorman River , ca. 2400 m ( MZB 448 , one of several specimens under this number, the remainder are Oreophryne sp. ) .

Figures

Fig. 39. Holotype of Oxydactyla alpestris, AMNH A76584, SVL 22.7 mm.