Oreophryne chlorops, Günther & Iskandar & Richards, 2023

Guenther, Rainer, Iskandar, Djoko T. & Richards, Stephen J., 2023, A new large Oreophryne species from the mountains of Papua Province, Indonesian New Guinea (Amphibia, Anura, Microhylidae), Vertebrate Zoology 73, pp. 153-159 : 153

Oreophryne chlorops sp. nov.

Figs 1 and 4

Holotype.

MZB.Amph.32875, adult male, unnamed mountain range, Derewo River Basin, Papua Province, Indonesia, (3.4416°S, 136.4738°E; ~2090 m a.s.l.), collected by Stephen Richards and Djoko Iskandar, 7th April 1998.

Diagnosis.

A species of Oreophryne based on the presence of eleutherognathine maxillae and clavicles that do not extend to the scapulae. Size large (>40 mm SUL); bony clavicle strongly curved; cartilaginous procoracoid reaching scapula; fifth toe slightly longer than third; tympanum not visible externally; iris blue-green in life; W-shaped scapular folds and eye spot in lumbar region present.

Description of the holotype.

Adult male (Fig. 1a-f ) with a snout-urostyle length of 41.6 mm. Additional measurements and body ratios are listed in Table 1 .

Snout subelliptical in dorsal view, rounded, scarcely protruding in profile; nostrils near tip of snout, directed laterally, not visible from above or below, distance between nares greater than distance between eye and naris (END/IND 0.90); canthus rostralis rounded; loreal region slightly skewed and slightly concave; tongue long, broad, free laterally and posteriorly without posterior indentation; posterior palatal ridge with 12 distinctly pronounced teeth; long vocal slits on both sides of mouth floor; tympanum not visible externally; prominent supratympanic fold present. Forelegs and hind legs moderately long; fingers unwebbed with large truncate, grooved terminal discs (disc of third finger 2.5 times wider than penultimate phalanx), their relative lengths 3> 4> 2> 1 (Fig. 1e ); all toes with wide, grooved terminal discs, those of fourth toe 1.8 times wider than penultimate phalanx; basal webbing present, most pronounced between toes 3 and 4 and least developed between toes 1 and 2; metatarsal and subarticular tubercles only faintly indicated as low protuberances; relative lengths of toes 4> 5> 3> 2> 1 (Fig. 1f ). A few tubercles on all dorsal and lateral surfaces, more conspicuous in life than in preservative; W-shaped mark in scapular region consists of short ridges and tubercles; lower surfaces of extremities smooth; abdomen, chest and throat slightly granular.

Colour in preservative: Dorsal surfaces of body and limbs (Fig. 1c ) broom yellow (RAL 1032) with a few light ivory (RAL 1015) markings on extremities, in lumbar region (eye spots) and snout and a few brown beige (RAL 1011) markings on forelimbs and laterally of the W-shaped dorsal mark. Ventral surfaces (Fig. 1d ) largely pearl white (RAL 1013), but forearms, lower legs and tarsi with ochre yellow (RAL 1024) patterns (as a result of Alcian Blue colouring parts of lateral surfaces, anterior surfaces of abdomen, and throat are now blue).

Colour in life: Dorsal and lateral surfaces of body and limbs beige (RAL 1001) or brown beige (RAL 1011) with beige-grey (RAL 7006) markings (Fig. 1a ). A conspicuous semilunar lumbar spot is ivory (RAL 1014) surrounded by brown beige flecks; and an irregular spot in the tympanal region is brown beige; ventral surfaces pale, unspotted. Iris largely pastel turquoise (RAL 6034) with black veining, except golden near pupil and blackish-brown patch anterior and posterior of central part of pupil (Fig. 1b ).

Distribution and ecological notes.

Oreophryne chlorops sp. nov. is known only from the type locality in the mountains of Papua Province, Indonesia (Fig. 2 ).

The habitat is very mossy, wet mid-montane rainforest on steep, rugged terrain at about 2000 m a.s.l (Fig. 3 ). The holotype was calling from a Pandanus frond at a height of approximately 4 m, but the call was not recorded. Nine species of frog were collected at the type locality, including three other species of Oreophryne , all of which are of uncertain taxonomic identity ( Richards et. al. 2000).

Suggested IUCN status.

Oreophryne chlorops sp. nov. is currently only known from a single locality. However, large areas of suitable habitat at similar elevations remain in nearby areas. Given the species’ poorly known distribution and that threats are poorly understood, we recommend that this species should be considered as Data Deficient at this stage.

Etymology.

The specific epithet is a combination of the ancient Greek adjective chloros meaning green, and the ancient Greek substantive ops meaning eye. Chlorops is a compound noun in apposition meaning green-eye and refers to the blue-green iris colour of the holotype.

Comparison with other species.

Oreophryne chlorops sp. nov. is distinguished from all congeners except Oreophryne anthonyi , O. idenburgensis and O. inornata by its very large size (adults exceeding 40 mm SUL). It can be distinguished from Oreophryne anthonyi and O. inornata by having a cartilaginous (vs. ligamentous) connection between the procoracoid and scapula, by its blue-green (pastel turquoise) iris in life (vs. dark brown in O. anthonyi and golden in O. inornata ) and by its beige dorsum and pale cream venter in life (vs. dorsum "dark-mottled yellow-brown to dark reddish brown" and venter plain yellowish white in O. anthonyi ; and dorsum orange-tan or yellow-tan and venter uniform lemon yellow in O. inornata ) ( Menzies 2006, Kraus 2016). Oreophryne chlorops is most similar to O. idenburgensis from which it can be distinguished by its hidden (vs. clearly detectable) tympanum, tapered (vs. truncate) snout in dorsal view (Fig. 4 ), broader head and smaller finger and toe discs (Tables 1 , 2 ), and in having (vs. lacking) prominent lumbar spots and distinct W-shaped scapular folds (Fig. 1a ). The major differences between these two species are summarised in Table 2 .

Figures

Figure 1. Adult male holotype of Oreophryne chlorops sp. nov.: a dorsolateral view of body; b lateral view of head, in life; c, d dorsal and ventral views of body; e, f palmar and plantar views, in preservative.

Figure 2. Distribution of four large Oreophryne species in the New Guinea region. Yellow star = O. chlorops sp. nov., red triangle = O. idenburgensis, green square = O. anthonyi and blue diamond = O. inornata. Green squares may cover more than one known location.

Figure 3. Wet mossy forest interior at the type locality of Oreophryne chlorops sp. nov.

Figure 4. Snout shape in dosal and ventral views of Oreophryne chlorops sp. nov. (a, b) and Oreophryne idenburgensis (AMNH A 49666) (c, d).