Platypelis efatra, Rakotoarison & Petzold & Scherz & Crottini & Köhler & Hawlitschek & Ratsoavina & Glaw & Vences, 2025

Rakotoarison, Andolalao, Petzold, Alice, Scherz, Mark D., Crottini, Angelica, Köhler, Jörn, Hawlitschek, Oliver, Ratsoavina, Fanomezana M., Glaw, Frank & Vences, Miguel, 2025, A new microhylid frog species of the genus Platypelis from phytotelmata of Pandanus screw pines in the Sorata massif, northeastern Madagascar, Zootaxa 5717 (3), pp. 383-402 : 390-396

publication ID	https://doi.org/10.11646/zootaxa.5717.3.5
publication LSID	lsid:zoobank.org:pub:DC6BAA01-2859-4A81-8134-C1B853B5545C
persistent identifier	https://treatment.plazi.org/id/515387DC-FF82-FFD4-76A5-FF28FC42FB8E
treatment provided by	Plazi
scientific name	Platypelis efatra
status	sp. nov.

Treatment

Platypelis efatra sp. nov.

Figures 4–5 View FIGURE 4 View FIGURE 5

Remark. Based on DNA sequences, this species has previously been referred to under the names P. tetra by Rosa et al. (2014), P. aff. tetra by Rakotoarison et al. (2020) and P. aff. tetra UCS “Sorata” by Carné & Vieites (2024).

Holotype. ZSM 1621/2012 (FGZC 3609), adult female with mature oocytes, collected on 26 November 2012, in the Sorata Massif (near 13.6817°S, 49.4411°E, 1339 m a.s.l.), now included in the protected area COMATSA Nord, northern Madagascar, by F. Glaw, O. Hawlitschek, T. Rajoafiarison, A. Rakotoarison, F.M. Ratsoavina, and A. Razafimanantsoa. GoogleMaps

Paratypes. Eight paratypes: ZSM 1619/2012 (FGZC 3671) and UADBA-FGZC 3672, two unsexed individuals collected on 28 November 2012, in the Sorata Massif (near 13.675°S, 49.4392°E, 1580 m a.s.l.) by the same collectors as the holotype; ZSM 1620/2012 (FGZC 3608), adult female with mature oocytes, and ZSM 1622/2012 (FGZC 3610), sex undetermined, with same collection data as the holotype; UADBA-FGZC 3633, UADBA-FGZC 3634 and UADBA-FGZC 3635, three unsexed individuals with same collection data as the holotype but collected on 27 November 2012; UADBA-FGZC 3688, a female, collected on 28 November 2012, in bamboo forest above the Sorata camp site by the same collectors as the holotype. The paratypes in the UADBA collection were not studied morphologically, but are genetically almost identical to the ZSM type specimens (see Fig. 1 View FIGURE 1 ) GoogleMaps .

Definition. Assigned to the genus Platypelis in the microhylid subfamily Cophylinae based on occurrence in Madagascar, enlarged terminal discs on fingers and toes, absence of nuptial pads, absence of femoral glands, and molecular phylogenetic relationships. The species can be distinguished from other cophylines by the combination of the following character states: (1) medium-sized species (adult female SVL 21.2–22.1 mm); (2) manus with second finger slightly shorter than fourth; (3) pes with third toe slightly longer than fifth; (4) dorsum with four symmetrically arranged and distinctly enlarged white tubercles; (5) absence of red color on limbs and ventral side; (6) absence of distinct yellow color on posterior belly and ventral sides of hindlimbs; (7) absence of greenish color on the throat and the belly; (8) presence of a dark dorsolateral stripe running from the eye to a point behind the axilla or further.

Diagnosis. Platypelis efatra sp. nov. differs from most specimens of Cophyla maharipeo , C. noromalalae and C. puellarum by smaller body size (SVL 19.4–22.1 mm vs. SVL up to 33.7 mm); from C. fortuna , C. occultans and C. phyllodactyla by having the third toe longer than fifth (vs. third toe slightly shorter than fifth); from C. berara by having the third toe longer than fifth (vs. both toes of similar length). Within Platypelis , the new species can be distinguished by a set of morphological characters from all congeners, of which we here highlight the most important characters. Platypelis efatra sp. nov. can be distinguished from all Platypelis species except for P. tetra , P. tuberifera and P. karenae by the presence of a dark band running from the eye to the forelimb insertion or beyond (vs. absence); from P. grandis , P. alticola and P. tuberifera by smaller body size (adult body size SVL 19.4–22.1 mm vs. 30–105 mm), and furthermore from P. grandis by largely smooth dorsal skin (vs. many large tubercles); from P. karenae by dorsal surface with dark markings and washed with irregular dark pigment (vs. typically uniformly yellowish light brown); from P. tuberifera and P. cowanii by smaller body size (adult SVL 19.4–22.1 mm vs. 30–40 mm); from P. tsaratananaensis and P. pollicaris by presence of four symmetrically arranged and distinctly enlarged white tubercles on dorsum (vs. absence); from P. ravus by presence of four symmetrically arranged and distinctly enlarged white tubercles on dorsum (vs. presence of moderately-sized tubercles); from P. olgae and from P. laetus by absence of greenish or green-yellow ventral color (vs. presence); from P. ando by the tibiotarsal articulation reaching between forelimb and tympanum when hindlimb adpressed along body (vs. reaching the tympanum); from P. milloti by absence of red ventral color and absence of distinct dorsal pattern of sharply delimited black markings and light vertebral stripe (vs. presence); from P. barbouri and P. ranjomena by absence of red color on ventral surfaces and limbs (vs. presence); from P. saikamavo by the absence of yellow coloration on the ventral side of belly and limbs (vs. presence); from P. mavomavo by absence of yellow color on belly (vs. presence in some populations) and smaller body size (adult SVL 19.4–22.1 mm vs. 21.8–32.3 mm).

Morphologically, the new species is most similar to P. tetra which, however, is phylogenetically not its closest relative. Due to a limited knowledge of the variation of P. tetra which may be a species complex, the following comparison is restricted to characteristics observed in the type material of P. tetra from Anjanaharibe Sud: the new species differs from these specimens according to data from Andreone et al. (2003), a photo probably corresponding to the holotype ( Fig. 3A View FIGURE 3 ), and our own examination of paratype MRSN A2172 by less distinct expression of symmetrical dorsal tubercles (four to six symmetrical tubercles visible, but especially the anterior pairs smaller than in P. tetra ), a distinct canthus rostralis (vs. possibly more indistinct), and possibly larger body size of females (up to 22.1 mm vs. up to 19.4 mm; Andreone et al. 2003). Osteologically, it differs most clearly by a well developed dorsal prominence and oblique groove on the iliac shafts (vs. indistinct), and more hatchet-shaped sacral diapophyses with an anteriorly angled anterior edge (vs. more triangular, with the anterior edge running perpendicular to the body axis). Several additional differences are present (see Comparative osteology section below), but their significance and consistency is difficult to assess without scans of more individuals per species.

Description of the holotype. Adult female, with mature oocytes visible through the ventral skin, in relatively good state of preservation ( Fig. 5 View FIGURE 5 ), some muscle tissue removed from left thigh; snout–vent length 21.2 mm (for further measurements see Table 1); body relatively plump; head slightly wider than long, not wider than body; snout slightly rounded in dorsal view, bluntly rounded in lateral view; nostrils not protuberant, nearer to tip of snout than to eye; canthus rostralis distinct, straight; loreal region straight, slightly oblique; tympanum distinct, 32.4% of eye diameter; supratympanic fold distinct, starting at posterior border of eye and ending anterior to forelimb; tongue long, broadening posteriorly, attached anteriorly, not notched; maxillary teeth present, vomerine teeth barely recognizable by superficial examination but present as two rudimentary aggregations posteriomedially to choanae; choanae rounded. Forelimbs robust; subarticular tubercles single, indistinct; outer metacarpal tubercle small, rounded; hand without webbing; terminal finger discs broadly rounded to slightly bilobate, with lateral fringes; relative length of fingers 1<2<4<3; nuptial pads absent. Hindlimbs slender; tibiotarsal articulation reaching between forelimb and tympanum when hindlimb adpressed along body; tibia length 47.6% of SVL; inner metatarsal tubercle small, oval; outer metatarsal tubercle absent; webbing between toes largely absent, limited to traces of webbing between third and fourth toe; subarticular tubercles on toes single; toes with flattened discs which are relatively broad and of slightly bilobate shape; relative length of toes 1<2<5<3<4; third toe slightly longer than fifth; skin dorsally smooth, without dorsolateral folds, with two distinctly enlarged and pointed symmetrical tubercles on the lower back and several smaller tubercles scattered on anterior back; ventral skin smooth.

After thirteen years in 70% ethanol, the dorsal surface is light brown, with dark brown markings distributed across the head, dorsum, and limbs. A distinct dark brown W-marking on the posterior dorsum, a dark X-marking on head and anterior dorsum. Additional elongated blotches and diffuse speckling are scattered across the dorsum, becoming denser along the flanks and dorsal surfaces of the thighs. Two symmetrically arranged distinct white tubercles are present on the posterior dorsum, several smaller white tubercles scattered on anterior back; symmetrical tubercles on anterior dorsum cannot be clearly recognized. The head is slightly darker than the rest of the dorsum, especially posterior to the eyes. A dark band runs from the eyes to almost reaching the forelimb insertion. Digits and toe tips are light brown, with dark brown color dorsally on hand, forearms, and thighs. The ventral surface is pale beige to yellowish cream.

In life ( Fig. 4 View FIGURE 4 ), similar to preservative but more contrasted. Some light color is visible dorsally, lining the dark W-shaped marking on the posterior dorsum and at the posterior edges of eyes. Two symetrically arranged white tubercles are also visible on the anterior dorsum (not clearly recognizable in preservative). The ventral side is uniformly gray-pinkish with a yellowish tint on the throat.

Variation. The examined paratypes agree well with the holotype in general morphology despite considerable individual variation in color pattern ( Fig. 4 View FIGURE 4 ). Paratype ZSM 1620/2012 (FGZC 3608) is a female with mature oocytes visible through the ventral skin, as in the holotype, and of similar body size as the holotype ( Table 1). ZSM 1622/2012 (FGZC 3610) is distinctly smaller and might be a male, but the prepollex on its hand is not strongly developed and we could not assess sexual maturity; in life, this specimen had two distinct light beige rhomboid markings in the central dorsum, and a rather yellowish throat ( Fig. 4 View FIGURE 4 )

Osteology. Based on a micro-CT scan of paratype ZSM1620/2012( Fig.6 View FIGURE 6 ). The skeleton shares key characteristics with other members of the genus Platypelis (given by Scherz et al. 2022): postchoanal and prechoanal vomer elements present; two small aggregations of vomerine teeth on the vomers, separated medially by a distinct gap; strongly curved clavicles starting near the midpoint of the coracoid; fingers and toes with Y-shaped distal phalanges. So far, no detailed description of the osteology of a Platypelis species has been published. We therefore provide such an account here:

Overall, the skeleton is well ossified, with all bones and bone endings clearly distinct. The skull is almost equilateral.

Dorsal investing bones. Nasals separated by a wide gap, without contact to any other bones, lachrymiform, with a very tapered and sharp maxillary process that does not approach the facial process of the maxilla. Frontoparietals well ossified, with a narrow gap separating them along the midline; in posterior contact with the exoccipital, lateral contact with the prootic, and anterolateral contact with the sphenethmoid. Dorsal surface smooth, without dorsal processes.

Neurocranium. Sphenethmoid ossified, forming a brace to the lateral anterior braincase between the frontoparietal above and parasphenoid cultriform process below, anteriorly extending beyond the tip of the cultriform process and ventrolaterally bracing the neopalatine.

Exoccipitals meeting only superficially dorsally and without contact posteriorly or ventrally, forming the fenestra ovale. Prootic substantially ossified; the prootic foramen (through which the trigeminal and other nerves pass) is not enclosed in this bone but presumably is closed anteriorly by the pila antotica. Septomaxilla curled, well ossified. Columella elongate, the pars interna plectri indented on its proximal surface, the anterodorsal surface continuous without substantial curve with the pars media plectri, the posteroventral surface distinctly set apart from the pars media plectri.

Ventral investing and palatal bones. Parasphenoid with broad and anteriorly subtly broadening cultriform process, short alary processes, and a bulbous posterior prominence that does not participate in the fenestra ovale. Posteriorly it is in contact with the exoccipitals, the prootics, and anteriorly with the sphenethmoids above, and neopalatines and/or posterior portions of the vomers below. Prechoanal vomer portion lunate, without distinct rami; postchoanal portion acuminate, bearing a small vomerine tooth aggregation separated broadly at the midline. The vomers approach but do not contact one another medially. Neopalatine curving, approaching the medial shelf of the maxilla but not contacting it.

Maxillary arcade and suspensorium. Premaxilla and maxilla bearing teeth. Premaxilla with a narrow medial and broader lateral process, and laterally slanted dorsal process. Maxilla weakly curved, with a narrow lingual shelf. Posteriorly broadly fused to the quadratojugal. Squamosal Y-shaped, otic ramus longer than zygomatic ramus, zygomatic ramus curving anteromedially. Pterygoid Y-shaped, the medial ramus strongly concave posteriorly, the anterior ramus running along the lingual surface of the maxilla, the posterior ramus apparently in synostotic contact with the quadratojugal and squamosal, forming a robust jaw joint.

Mandible. Mentomeckelians small, hourglass shaped. Dentary practically unossified, visible only as a shadow in our micro-CT scan reconstructions. Angulosplenial curved similarly to maxilla; articular facet broadened and inflected slightly ventrally.

Pectoral girdle. No ossified prezonal elements present. Coracoids strongly flared medially, about twice as wide as at the glenoid socket. A weakly mineralized sternum is present. Clavicles thin, strongly curved, more strongly than the anterior surface of the coracoid; starting around the middle of the coracoid. Scapula rather short and broad, with a concave dorsal articulation with the cleithrum. Cleithrum with a well mineralized base and anterior edge, with expanded ossification also at the dorsal end. Suprascapula largely unossified.

Humerus robust, with distinctly raised ventral and lateral crests. Radioulna substantially broadened distally. Ulnare, carpale, carpals 2, 3–5 present. Carpal formula 2-2-3-3, with strongly Y-shaped terminal phalanges on all digits.

Vertebral column. Eight procoelous presacral vertebrae, as typical for Cophylinae . Atlas with notably large occipital condyles, almost complete dorsally. Transverse processes rather short and broad, only those of III longer than the centrum is wide; those of II–IV substantially broader than V–VIII. Directions of transverse processes: II, anteroventrolateral; III, posterolateral; IV, posterolateral; V, lateral; VI, slightly anterolateral; VII, more strongly anterolateral; VIII, parallel to VII. No distinct dorsal processes on vertebrae, except a small bulbous anterior projection on II. Sacrum broader than all other vertebrae except III; sacral diapophyses hatchet-shaped, with a straight portion ca 1/3 rd of the posterior edge, then bending posteriorly; the distal edge is curved; articulation with urostyle bicondylar. Iliosacral articulation type IIA sensu Emerson (1979); a mineralized extension posterolateral to the diapophysis over the iliac shafts. Urostyle with a dorsal ridge along over half of its length.

Pelvic girdle. Iliac shafts without noticeable dorsal crests. Oblique groove distinct, dorsal prominence very well developed. Pubis and ischium well ossified. Femur slightly sigmoid, with a distinct and low posterior crest. Tibiofibula straight, with a small bulge in the middle. Ulnare-fibulare fused proximally and distally. Mesopodial elements comprising a well developed prehallux, a centrale, and tarsals 1 and 2+3. The toe formula is standard (2- 2-3-4-3). The proximal phalange of toe I is very short. Terminal phalanges of all toes Y-shaped, with the arms of the Y as wide or wider than the proximal articulation.

Etymology. The species epithet is a noun in apposition, derived from the Malagasy word efatra = four, making reference to the superficial morphological similarity of the new species to P. tetra , whose species epithet also means four in Latinized Greek, referring to the four symmetrical tubercles on its dorsum.

Natural History. Specimens were found in Pandanus leaf axils in rainforest. Advertisement calls were not recorded (see below an updated call description for P. tetra ). In the holotype, and in paratype ZSM 1620/2012, oocytes as visible through the ventral skin are unpigmented and about 2 mm in diameter. Tadpoles unknown.

Distribution. The species is known from (1) its type locality, the Sorata Massif, and from two further sites based on DNA sequences provided by Peloso et al. (2016) and Rosa et al. (2014), namely (2) Andramanalana (voucher specimen RAX 10391) and (3) Lohanandroranga (voucher specimen RAX 6660 (AMNH A167267)) (see Fig. 2 View FIGURE 2 ). The elevational range in the Sorata massif is 1339–1558 m a.s.l.