Cophixalus flavopunctatus Günther, Nagombi & Richards, 2025, sp. nov.

Cophixalus flavopunctatus sp. nov. urn:lsid:zoobank.org:act: 879302FF-B5F9-44BD-8667-8F6896881523 Figs 1–2 Holotype. SAMA R72173 (Field Number: SJR 13431), adult male, Papua New Guinea, Gulf Province, Purari Hydro Camp 4 (7.5669°S, 145.2539°E; 60 m a.s.l.), collected by S.J. Richards on 30 October 2011. Paratypes (n = 11). All Papua New Guinea, Gulf Province. SAMA R72174 (FN SJR 13432), adult male, ZMB 94721 (FN SJR 13433), subadult, same details as holotype; SAMA R72172 (FN SJR 14970), adult male, ZMB 94722 (FN SJR 14969), adult female, Total PLNG Site 1 (7.1464°S, 145.1408°E; 100 m a.s.l.), collected by S.J. Richards and E. Nagombi on 21 and 22 January 2016 respectively; SAMA R72423 (FN SJR 14436), R72425 (FN SJR 14437), both adult females, Purari Hydro Staging Camp (7.0525°S, 145.2453°E; 50 m a.s.l.), collected by S.J. Richards on 14 July 2011; SAMA R72424 (FN SJR 14320), R72426 (FN SJR 14315), adult females, Purari Hydro Camp 8 (6.9438°S, 145.1031°E; 90 m a.s.l.), collected by S.J. Richards on 28 and 26 June 2012 respectively; SAMA R72419 (FN SJR 14361) adult male, Purari Hydro Camp 9 (6.97614°S, 144.9920°E; 100 m a.s.l.), collected by S.J. Richards on 1 July 2012; SAMA R72427 (FN SJR 15066), PNGMN (FN SJR 15090), adult females, Total PLNG Site 3 (7.4910°S, 145.2189°E; 145 m a.s.l.), collected by S.J. Richards and E. Nagombi on 3 and 6 February 2016 respectively. Diagnosis. The new species is assigned to Cophixalus Boettger, 1892 on the basis of the following combination of characters: jaws eleutherognathine; clavicles and procoracoids absent; third toe longer than fifth; and nesting in the Cophixalus clade according to molecular data presented by Richards et al. (2021). We follow Frost (2024) in not accepting the recommendation of Dubois et al. (2021) to synonymise the genus name Cophixalus with Asterophrys Tschudi, 1838. Distinguished from congeners by its small size (SUL 13.5–15.5 mm in 11 mature specimens) and the following unique combination of characters: head relatively short (HL/SUL 0.30–0.34); legs relatively long (TL/SUL 0.53– 0.58); third toe clearly longer than fifth; terminal discs of fingers larger than or same size as those of toes; dorsal skin ridges restricted to scapular region; dorsal and lateral surfaces in life grey- to green-beige with conspicuous saffron yellow (RAL 1017) tubercles; loreal region not black; advertisement call with 22–27 peeping notes, the first ones longer than subsequent notes, with repetition rate of 1.77–2.04 notes/s and peak of dominant frequency at 4.8–4.9 kHz. Description of the holotype (Fig. 1A–F). For measurements see Table 1. Head slightly broader than long (HL/HW 0.94); canthus rostralis well defined; loreal region concave; snout weakly protruding in profile, rounded in dorsal and ventral views; nostrils close to canthus rostralis and near tip of snout (Fig. 1A); eye diameter longer than eye-naris distance (ED/END 1.27); tympanum poorly defined, half size of eye (TyD/ED 0.50); internarial distance slightly less than eye-naris distance (END/IND 0.94); tongue strap-shaped, free laterally and posteriorly, posterior margin with shallow indentation; prepharyngeal ridge weakly developed with indistinct dermal denticles; vocal slits on both sides of tongue clearly pronounced. Dorsally skin smooth with irregularly distributed tubercles, these much more pronounced in life than in preservative. Scapular region with W-shaped glandular ridges, abdomen slightly granular, all remaining ventral surfaces smooth (Fig. 1A–D). Legs relatively long (TL/SUL 0.55); no webbing between fingers and toes; tips of finger 1 and toe 1 slightly expanded, discs on other fingers and toes wider, all with circum-marginal grooves; disc of toe 4 narrower than disc of finger 3 (T4D/F3D 0.86); relative lengths of fingers 3> 4> 2> 1 (Fig. 1E); third toe longer than fifth, relative length of toes 4> 3> 5> 2> 1 (Fig. 1F); subarticular tubercles on fingers and toes and inner metatarsal tubercle scarcely developed. Colour in life. Iris light yellow dorsally and ventrally, yellow orange (RAL 2000) anteriorly and posteriorly, entire iris with very sparse dark brown veining. Dorsal surfaces predominantly grey-beige (RAL 1019) with blackbrown (RAL 8022) and light ivory (RAL 1015) blotches (Fig.1A). Dorsolateral surfaces of body and dorsal shanks with conspicuous saffron yellow tubercles. Ventral surfaces pearl white (RAL 1013) with blackish speckles on throat, sides of abdomen and posterior shanks. Posterior abdomen and ventral shanks with yellowish hue (Fig. 1B). Colour in preservative. Dorsal surfaces brown, with variably dense covering of clay-brown (RAL 8003) dots; canthal stripe terra-brown (RAL 8028); W-shaped scapular ridges, dorsolateral and lateral spots on body, and flecks on posterior dorsum and on dorsal limbs terra-brown (Fig. 1C). Basic colour of ventral surfaces light-ivory (RAL 1015); abdomen unspotted; throat, chest and limbs covered with variably dense clay-brown dots (Fig. 1D). Dorsal and lateral tubercles that were saffron yellow in life have become pale ivory (RAL 1015) in preservative. Variation. Body length of four adult Cophixalus flavopunctatus sp. nov. males is 13.5–14.8 mm and of seven adult females is 13.8–15.5 mm. One specimen with an SUL of 12.3 mm is subadult. Variation in measurements and body ratios of the type series is minimal (Table 1). Base colour of dorsal surfaces in life varies from grey-beige (Fig. 1A) to green-beige (RAL 1000) (Fig.1G) and dorsal spots are dark brown or blackish in life and in preservative and vary in number and intensity. Eight of the 12 type specimens exhibit a W-shaped mark on the anterior dorsum and all 12 type specimens exhibit a light interocular stripe which is delimited posteriorly by a dark brown stripe or a brown area. Only one specimen (SAMA R72425) lacks mottling on dorsal surfaces. Base colour of ventral surfaces in preservative light-ivory, abdomen without or with only a few spots; throat, anterior chest and lower surfaces of hind limbs covered with copper-brown (RAL 8004) and/or dark brown spots of variable intensity. Colour in life of three specimens, the holotype and paratypes SAMA R72172 and R72174, was documented. Like the holotype, saffron yellow tubercles on dorsal and lateral surfaces of these two paratypes changed to light ivory in preservative. It is likely that light ivory dorsal and lateral tubercles, including conspicuous tubercle posteroventral of tympanum that is exhibited by most of the type series, were saffron yellow in life. Vocalization. We analysed in detail one advertisement call from the holotype, SAMA R72173, recorded at an air temperature of 28°C. The call is a note series containing 27 harmonic notes sounding like “eep-eep-eep” with a repetition rate of 2.04 notes/s and lasting 13.25 s (Fig. 2A). Note length decreases gradually during the call. The first note is the longest (353 ms), followed by four shorter notes longer than 300 ms, nine notes between 236–277 ms and the remaining 13 notes between 208–240 ms. Mean note length is 248±39 ms, range 208–353 ms and mean inter-note interval is 254±65 ms, range 210–532 ms. Notes start sharply with maximum amplitude, which then has an irregular pattern and ends more or less abruptly (Fig. 2B). There are six harmonics; the fundamental frequency is very weakly expressed at 2.45 kHz and the dominant frequency is focused around 4.90 kHz (Fig. 2C, D). Two additional unvouchered calls recorded at the same locality and temperature that we refer to this species last 11.9 and 12.6 s and contain 22 and 23 notes produced at a repetition rate of 1.8 notes/s. Dominant frequency is 4.8–4.9 kHz. The call produced by the holotype is available on Xeno-Canto (XC964725). Distribution, habitats and habits. Cophixalus flavopunctatus sp. nov. is known from a handful of localities in the lowland forests of Gulf Province, Papua New Guinea (Fig. 6). These are centred on the Purari River Basin but calls tentatively associated with this species have also been heard at Kopi in the adjacent Kikori River Basin (Fig. 6). Males call sporadically during the morning and late afternoon, particularly after rain, from within litter on the forest floor. Calling was rarely heard at night and no individuals were encountered in elevated positions on low foliage. Calling sites were concentrated on the banks of deeply dissected creek lines in lowland rainforest (Fig. 3), but some individuals were heard calling from more gently sloping terrain. This species occurs in sympatry with at least 23 other microhylid frogs at sites where it was documented in the Purari Basin: Asterophrys slateri Loveridge, 1955, Austrochaperina cf. palmipes, Austrochaperina sp., Callulops marmoratus, Ca. taxispilotus Kraus, 2019, Choerophryne alainduboisi Günther & Richards, 2018, Ch. bickfordi, Ch. crucifer Günther & Richards, 2017, Cophixalus cheesmanae Parker, 1934, Cophixalus hannahae Richards & Günther, 2019, Copiula derongo (Zweifel, 2000), Copiula sp. (probably mosbyae), two undescribed Hylophorbus species, Mantophryne lateralis Boulenger, 1897, Oreophryne nicolasi Richards & Günther, 2019, O. oviprotector Günther, Richards, Bickford & Johnston, 2012, O. pseudunicolor Günther & Richards, 2016, the new Oreophryne species described below, Sphenophryne cornuta Peters & Doria, 1878, S. schlaginhaufeni Wandolleck, 1911, Xenorhina lacrimosa and X. pohleorum Günther & Richards, 2021. Etymology. The specific epithet is a compound adjective; flavus is a masculine Latin adjective and means yellow and punctatus is Latin for dotted. Flavopunctatus refers to the yellow dots on various dorsal surfaces of the new species. Comparison with other species. Below we compare the new species with all New Guinean congeners of a similar size (SUL ~ 13.5–15.5 mm). Cophixalus flavopunctatus sp. nov. can be distinguished from the following species by having the finger discs clearly broader than the toe discs (vs. finger discs narrower or the same si