Liophryne rubra, 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 : 65-68

Liophryne rubra , new species Figure 35

HOLOTYPE: UPNG 9361 (field no. 97), collected by Tamari Mara on October 3–9, 1995, in Western Highlands Province, Papua New Guinea, about 3 km east of Mt. Opio (5°35′51̎S, 144°47′25̎E) at an elevation of 2180 m.

PARATYPE: UPNG 4147, collected by G. George in July 1973 in the Kubor Range, Western Highlands Province, Papua New Guinea. No more specific data are available.

ETYMOLOGY: The Latin adjective rubra refers to the red color in life.

DIAGNOSIS: A Liophryne of moderate size (SVL about 37 mm in two specimens), similar in size to L. dentata and L. schlaginhaufeni but differing from these in its shorter eye–naris distance (EN/SVL maximum 0.076 vs. minima of 0.082 and 0.091 in dentata and schlaginhaufeni ), wider average internarial span (mean IN/SVL 0.134 vs. maxima of 0.109 and 0.116), and lack of scapular skin folds. L. dentata differs additionally in having a postocular skin fold that curves downward behind the ear rather than continuing straight onto the flank.

DESCRIPTION OF HOLOTYPE: The holotype specimen is a mature female (2-mm ova), with the following measurements and proportions (those of the single paratype given in parentheses): SVL 37.5 (37.0), HW 15.0 (14.5), TL 21.1 (21.0), EY 4.0 (4.1), EN 2.8 (2.8), IN 4.9 (4.3), TY 3.2 (2.8), HD 8.3 (8.0), FT 19.9 (18.4), disc of third finger 1.1 (0.09), penultimate phalanx 0.06 (0.05), disc of fourth toe 1.7 (1.4), penultimate phalanx 0.8 (0.08), TY 3.2 (2.8); HW/SVL 0.400 (0.392), TL/SVL 0.563 (0.568), EY/SVL 0.107 (0.111), EN/SVL 0.075 (0.076), IN/ SVL 0.131 (0.116), EN/IN 0.571 (0.651), HD/SVL 0.221 (0.216), FT/SVL 0.528 (0.497), FD/SVL 0.029 (0.024), TD/SVL 0.045 (0.038).

Head narrower than the rather robust body, snout bluntly pointed seen from above, rounded and slightly projecting in profile; nostrils lateral, barely visible from above, slightly closer to eye than to tip of snout; canthus rostralis distinct, slightly rounded; loreal region steep, nearly flat. Eyes moderate in size, corneal outline visible from beneath, interorbital span about 1.5X width of eyelid. Tympanum relatively large and smooth. Relative lengths of fingers 4> 3> 2> 1, first relatively long, reaching to base of disc of second, all with discs broader than penultimate phalanges; subarticular elevations moderately prominent, rounded. Relative lengths of toes 4> 3> 5> 2> 1, first short, reaching base of subarticular elevation of second, all with discs broader than penultimate phalanges, disc of fourth toe about 1.5X width of that of third finger; subarticular elevations moderately prominent, rounded; inner metatarsal elevation low, rounded. A straight fold of skin passing from posterior corner of eye diagonally on flank where it fades out; skin otherwise smooth with no dorsal tubercles or scapular folds. There appear to be small maxillary teeth.

Shortly after being preserved, the specimen was ‘‘bright chestnut red’’ in color (J. Menzies, personal commun.); the dorsal surfaces (head, body, legs, and feet) have since faded to pale yellowish tan, unmarked except for a white vertebral hairline. A dark streak passes from nostril to eye and resumes at the posterior corner of the eye to include much of the ear before terminating (fig. 36). The streak is sharply defined at the canthus rostralis, less so along its lower edge; the upper lip is pale. The ventral surfaces are pale and unmarked from chin to hind legs. There are a few dark marks on front and rear surfaces of the front legs, an irregular longitudinal dark streak on the anterior side of each thigh, and a poorly defined dark streak on the posterior side. The palms and soles have some dark pigment but are not wholly dark.

VARIATION IN TYPE SERIES: The paratype resembles the holotype in all pertinent characters, most notably the relatively short eyenaris span, absence of convergent scapular folds, and color pattern. Body proportions are summarized in table 6.

REFERRED SPECIMEN: A specimen of Liophryne 9 from the Baiyer River region some

9 SAMA R23853, collected by Thomas Burton Jan. 3, 1982, at Trauna Ridge, 1750 m, 13 km E Baiyer River Wildlife Sanctuary, Western Highlands Prov., Papua New Guinea.

75 km west-northwest of the type locality of L. rubra and at a lower elevation (1750 m) may represent this species. It is a male, maturity not determined, but at SVL 25.7 mm it is smaller than the known size of maturity of male schlaginhaufeni (29 mm). Thomas Burton (personal commun.) described the living frog as rich reddish brown above and orange below (deepest in the throat region) with white flecking and white spots edging the mandible. This specimen also has a pale midventral hairline intersected by a similar line running between the arms. In the critical EN measurement it falls outside the range of schlaginhaufeni of similar size and in the same direction as the holotype (fig. 37). I tentatively regard this specimen as rubra , but do not accord it paratype status as I have not compared it directly with the holotype and paratype, and hence it does not contribute to my characterization of the new species.

ILLUSTRATIONS: Hand and foot, fig. 54A. Burton’s (1986: figs. 7C, 11D, 21C) illustrations of throat and jaw musculature and anterior view of mandibles of Sphenophryne schlaginhaufeni may represent L. rubra (see Remarks, below).

CALL: The call has not been described.

COMPARISONS WITH OTHER SPECIES: In most respects the proportions of this species are within the range of variation of Liophryne schlaginhaufeni of similar size, but there is a significant exception, the eye–naris distance being much shorter than in schlaginhaufeni (fig. 37). If the absence of convergent scapular folds proves to be consistent, this too will be diagnostic. Also, schlaginhaufeni , recorded from about 400–1550 m, is not known from such a high elevation (2180 m; but see Referred Specimen). L. dentata differs from rubra in the same way in eye–naris proportions and in its curved rather than straight postocular fold.

HABITAT AND HABITS: Nothing is on record for the holotype. Thomas Burton (in litt.) reported finding the referred specimen under leaf litter and another, larger male accompanying eggs.

DISTRIBUTION: This species is known from the central ranges of Papua New Guinea — the type locality in the Bismarck Range, the Kubor Mountains, and possibly from a locality about 75 km west-northwest of the type locality in the highlands of Papua New Guinea (fig. 38).

Figures

Fig. 35. Holotype of Liophryne rubra, UPNG 9290, SVL 37.5 mm.