identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
389F341351AB51008B00184A371B251C.text	389F341351AB51008B00184A371B251C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Vietnamophryne abscondita Poyarkov & Gorin & Le & Trofimets & Duong & Nguyen & Pawangkhanant & Suwannapoom & Nguyen 2026	<div><p>Vietnamophryne abscondita sp. nov.</p><p>Figs 4, 5, Table 3</p><p>Holotype.</p><p>VRTC NAP-12097 (field tag NAP-12097), adult male, from limestone karst forest, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=105.88199&amp;materialsCitation.latitude=17.820354" title="Search Plazi for locations around (long 105.88199/lat 17.820354)">Kim Dien Commune</a>, Quang Tri Province, Vietnam (17.820355 ° N, 105.881989 ° E; elevation ca. 250 m a. s. l.), collected by D. T. Nguyen, T. V. Duong, N. A. Poyarkov on 20 May 2022.</p><p>Paratype (n = 1).</p><p>ZMMU A-8446 (field tag NAP-12098), adult male, with the same collection information as the holotype .</p><p>Diagnosis.</p><p>The new species Vietnamophryne abscondita sp. nov. is distinguished from all of its congeners by a combination of the following morphological characters: (1) medium body size (SVL 18.1–19.0 mm in males, n = 2); (2) head slightly wider than long; (3) snout short, rounded in dorsal view; (4) tympanum indistinct; (5) dorsal skin finely shagreened, lacking enlarged tubercles or a median dorsal ridge; (6) finger I longer than half of finger II (1 FL / 2 FL ratio 59.8–71.9 %); (7) toes without webbing, bearing rounded terminal discs; (8) forelimbs and hindlimbs slender; (9) dorsum dark brown to chocolate brown with irregular lighter mottling; (10) flanks and limbs densely speckled with pale spots; (11) ventral surface bright yellow-orange to orange on chest and belly, with dark marbling on throat and ventral surfaces of limbs; (12) lower jaw region with scattered pale blotches; and (13) indistinct pale yellow suborbital spotting extending from eye toward mouth corner.</p><p>Description of holotype.</p><p>Adult male (Figs 4 A – E, 5 A), specimen in good state of preservation. Body habitus stout, miniaturized (SVL 18.14 mm). Head slightly wider than long (HL / HW 0.93); snout short and rounded in dorsal view (Fig. 4 A), rounded in profile (Fig. 4 C), longer than eye diameter (SL / EL 1.33). Eyes medium-sized, slightly protuberant in dorsal and lateral views (Fig. 4 C); pupil round. Dorsal surface of head slightly convex; canthus rostralis rounded and indistinct; loreal region weakly concave; nostrils rounded, lateral, positioned approximately equidistant between snout tip and eye. Tympanum indistinct; supratympanic fold present, glandular. Vomerine teeth and vomerine spikes absent; a single transverse smooth palatal fold present anterior to the pharynx; tongue spatulate, free posteriorly, without papillae; vocal sac openings not discernible.</p><p>Forelimbs comparatively short, approximately one-third of hindlimb length (FLL / HLL 0.53); hand shorter than lower arm, approximately half of forelimb length (HAL / FLL 0.43). Fingers short, slender, rounded in cross-section; Finger I well developed, exceeding half the length of Finger II (1 FL / 2 FL 0.60); relative finger lengths I &lt;II &lt;IV &lt;III (Fig. 4 D). Finger webbing and dermal fringes absent. First fingertip slightly protuberant, forming a small nub; tips of Fingers II – IV rounded, not dilated; finger discs absent; terminal grooves absent. Subarticular tubercles under fingers indistinct; nuptial pads absent. Two palmar tubercles present: inner palmar tubercle small and rounded; outer palmar tubercle rounded with indistinct margins, slightly shorter than inner palmar tubercle (IPTL / OPTL 0.87); palmar surface smooth; supernumerary palmar tubercles absent.</p><p>Hindlimbs comparatively short and robust; tibia length approximately half of snout – vent length (TL / SVL 0.51); tibiotarsal articulation of adpressed limb reaching eye level. Foot slightly shorter than tibia (FL / TL 1.39). Relative toe lengths I &lt;II &lt;V &lt;III &lt;IV (Fig. 4 E). Toes rounded in cross-section; toe webbing absent; dermal fringes absent; tips of Toes III and IV slightly dilated, terminal grooves absent. Subarticular tubercles under toes indistinct. Single metatarsal tubercle present: inner metatarsal tubercle rounded and flattened (IMTL / 1 TOEL 0.52); outer metatarsal tubercle absent.</p><p>Skin on dorsum finely shagreened, covered with dense, low, rounded granules giving a slightly roughened but not warty appearance. No enlarged tubercles, dorsolateral ridges, or median dorsal ridge present. Dorsal granulation more evident under oblique light, forming a uniform, finely textured surface across head, body, and dorsal surfaces of limbs. Posterior dorsum without clustered pustules or enlarged nodules. Skin on flanks similarly shagreened, with granules slightly more pronounced than on mid-dorsum; no glandular ridges observed. Dorsolateral white spots irregular in shape and size, scattered diffusely along flanks and lateral surfaces of head and body; spots not arranged in a distinct linear series. Head skin finely granular; loreal and temporal regions shagreened. Upper eyelid smooth to very finely granular. Skin on dorsal surfaces of forelimbs and hindlimbs finely shagreened, matching dorsal trunk texture. Ventral surfaces of limbs smooth, lacking granules. Skin on throat, chest, and belly smooth, glossy in life, without visible granulation or folds except for a single transverse palatal fold internally. No ventral dermal tubercles or asperities observed. Ventral skin appears thinner and more translucent than dorsal skin.</p><p>Coloration in life</p><p>(Fig. 5 A). Dorsal surfaces dark brown to chocolate brown, densely mottled with irregular lighter brown and yellowish speckles, producing a marbled appearance; head slightly darker than dorsum, with diffuse pale yellow spotting on loreal, suborbital, and temporal regions, extending from eye toward mouth corner. Flanks and dorsal surfaces of limbs heavily speckled with small pale yellow to cream spots. A faint pale supralabial stripe present. Ventral surface bright yellow-orange to orange on chest and belly, gradually fading to paler yellow toward the groin; throat and ventral surfaces of limbs with irregular dark brown marbling. Lower jaw region with scattered pale blotches; palms and soles greyish with diffuse pale mottling.</p><p>Variation.</p><p>The paratype ZMMU A-8446 (Figs 4 F, 4 G, 5 B) generally agrees with the holotype in overall morphology and coloration but is slightly larger in body size (SVL 19.04 mm vs. 18.14 mm in the holotype). Minor variation is observed in coloration, with the paratype exhibiting a darker dorsal background and less contrasting pale mottling. Ventral yellow-orange coloration is slightly paler, and dark marbling on the throat and ventral surfaces of limbs is less pronounced. Dorsal skin texture in the paratype is similarly finely shagreened, without enlarged tubercles or dorsal ridges.</p><p>Measurements</p><p>(in mm): Holotype (VRTC NAP-12097; adult male): SVL 18.14; HL 6.36; HW 6.85; SL 2.19; EL 1.65; N – EL 1.47; IND 1.98; IOD 2.23; UEW 1.01; FLL 9.61; LAL 7.91; HAL 4.11; 1 FL 0.70; 2 FL 1.17; 3 FL 2.28; 4 FL 1.70; IMTL 0.48; 1 TOEL 0.93; 2 TOEL 1.90; 3 TOEL 3.15; 4 TOEL 4.89; 5 TOEL 2.15; IPTL 0.48; OPTL 0.55. Paratype (ZMMU A-8446; adult male): SVL 19.04; HL 6.53; HW 7.32; SL 2.48; EL 1.87; N – EL 1.38; IND 2.39; IOD 2.58; UEW 1.20; FLL 10.49; LAL 8.46; HAL 4.34; 1 FL 0.87; 2 FL 1.21; 3 FL 2.38; 4 FL 1.84; IMTL 0.54; 1 TOEL 0.93; 2 TOEL 2.15; 3 TOEL 3.20; 4 TOEL 5.07; 5 TOEL 2.52; IPTL 0.49; OPTL 0.57.</p><p>Etymology.</p><p>The specific name is a Latin adjective in the nominative singular, derived from absconditus, meaning “ hidden, ” “ secret, ” or “ concealed. ” The name refers to the secretive semifossorial lifestyle of the species, which inhabits leaf litter and soil within limestone crevices and grottos in karst formations of Quang Tri Province, Vietnam. The following common names are recommended: “ Karstic Dwarf Frog ” (English), “ Nhái lùn đá vôi ” (Vietnamese), and “ Карстовый узкоротик ” (Karstovyi uzkorotik, Russian).</p><p>Comparisons.</p><p>Vietnamophryne abscondita sp. nov. steadily differs from all currently recognized species of Vietnamophryne in having tympanum completely hidden by the skin of glandular supratympanic fold (vs. tympanum externally visible in all other congeners). Other diagnostic characters distinguishing the new species from all currently recognized congeners are summarized in Table 3. Below, individual comparisons of Vietnamophryne abscondita sp. nov. with other Vietnamophryne species are provided.</p><p>Vietnamophryne abscondita sp. nov. further differs from V. aurantifusca by slightly larger male body size (SVL 18.1–19.0 mm vs. 17.6–18.2 mm), brighter ventral coloration (bright yellow-orange vs. orange), darker dorsal background (dark brown to chocolate brown vs. reddish- to orange-brown), dense pale speckling on dorsum, flanks, and limbs (vs. few dorsal pustules posteriorly), more conspicuous dark marbling on throat and ventral surfaces of limbs (vs. weak gray marbling), and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Vietnamophryne abscondita sp. nov. further differs from V. cuongi by slightly larger male body size (SVL 18.1–19.0 mm vs. female SVL 16.9–18.1 mm), although this comparison should be interpreted with caution due to the absence of male specimens for V. cuongi; darker dorsal background (dark brown to chocolate brown vs. brown to reddish-brown); dense pale speckling on dorsum and limbs (vs. few dorsal pustules posteriorly); absence of a distinct whitish canthal stripe and brick-red supratympanic tubercles (vs. present); brighter ventral coloration (bright yellow-orange with conspicuous dark marbling vs. milky white with gray marbling); and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Vietnamophryne abscondita sp. nov. further differs from V. inexpectata by larger male body size (SVL 18.1–19.0 mm vs. 14.2 mm); more developed first finger in males (1 FL / 2 FL 0.60–0.72 vs. 0.30); finely shagreened dorsal skin lacking enlarged posterior pustules (vs. dorsum mostly smooth anteriorly, becoming shagreened posteriorly with conspicuous large flat pustules); darker dorsal background (dark brown to chocolate brown vs. reddish-brown); brighter ventral coloration (bright yellow-orange with conspicuous dark marbling vs. lemon-yellow with fine brown marbling); and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Vietnamophryne abscondita sp. nov. further differs from V. occidentalis by smaller male body size (SVL 18.1–19.0 mm vs. 20.5 mm); darker dorsal background (dark brown to chocolate brown vs. reddish-brown); dense pale speckling on dorsum and limbs (vs. more uniform reddish dorsum with sparse speckling); absence of enlarged posterior dorsal pustules (vs. present); brighter ventral coloration (bright yellow-orange with conspicuous dark marbling vs. orange with weak or absent marbling); and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Vietnamophryne abscondita sp. nov. further differs from V. orlovi by larger male body size (SVL 18.1–19.0 mm vs. 15.4 mm); more developed first finger in males (1 FL / 2 FL 0.60–0.72 vs. 0.50); darker dorsal background (dark brown to chocolate brown vs. reddish-brown); denser pale speckling on dorsum and limbs (vs. more uniform reddish dorsum with sparse speckling); absence of enlarged posterior dorsal pustules (vs. present in V. orlovi); brighter ventral coloration (bright yellow-orange with conspicuous dark marbling vs. lemon-yellow with weaker marbling); and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Finally, Vietnamophryne abscondita sp. nov. further differs from V. vuquangensis by larger male body size (SVL 18.1–19.0 mm vs. 14.1–14.9 mm); more developed first finger in males (1 FL / 2 FL 0.60–0.72 vs. 0.43–0.49); darker dorsal background (dark brown to chocolate brown vs. light to medium brown); denser pale speckling on dorsum and limbs (vs. more uniform dorsum with sparse speckling); finely shagreened dorsal skin (vs. mostly smooth dorsum); brighter ventral coloration (bright yellow-orange with conspicuous dark marbling vs. ivory-lemon to lemon-yellow); and presence of indistinct pale yellow suborbital spotting extending from eye toward mouth corner (vs. absent).</p><p>Distribution, natural history, and conservation status.</p><p>Vietnamophryne abscondita sp. nov. is currently known only from its type locality in limestone karst forests of Quang Tri Province, central Vietnam. Specimens were found in leaf litter and soil microhabitats at the entrance to a small cave within an evergreen karst forest, suggesting a semi-fossorial lifestyle similar to that reported for congeners. The new species was recorded in syntopy with a rhacophorid frog Gracixalus quyeti (Nguyen, Hendrix, Böhme, Vu &amp; Ziegler, 2008), which was found in the same limestone cave.</p><p>Although the species is presently documented from a single locality, extensive limestone karst formations occur throughout Quang Tri Province and adjacent areas, indicating that it may have a broader distribution than currently recognized. Forest habitats in these karst regions are subject to anthropogenic pressures, including deforestation, habitat fragmentation, land-use conversion associated with Acacia plantations, infrastructure development, and livestock grazing. However, there is currently no evidence of population decline, severe fragmentation, or extreme fluctuations. Given the presumed wider distribution and lack of direct information indicating significant threats at the population level, it is provisionally suggested that Vietnamophryne abscondita sp. nov. be classified as Least Concern (LC) under the IUCN Red List Categories and Criteria, pending further field surveys to clarify its true range and conservation status.</p></div>	https://treatment.plazi.org/id/389F341351AB51008B00184A371B251C	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Poyarkov, Nikolay A.;Gorin, Vladislav A.;Le, Son Xuan;Trofimets, Alexei V.;Duong, Tang Van;Nguyen, Duc Trong;Pawangkhanant, Parinya;Suwannapoom, Chatmongkon;Nguyen, Tan Van	Poyarkov, Nikolay A., Gorin, Vladislav A., Le, Son Xuan, Trofimets, Alexei V., Duong, Tang Van, Nguyen, Duc Trong, Pawangkhanant, Parinya, Suwannapoom, Chatmongkon, Nguyen, Tan Van (2026): More dwarfs: a new microendemic species of Vietnamophryne (Anura, Microhylidae) from limestone karst of Quang Tri Province, Central Vietnam. Herpetozoa 39: 145-160, DOI: 10.3897/herpetozoa.39.e191333
