[Mammalogy • 2026] Coendou sangay • A New Species of Coendou (Rodentia: Erethizontidae) within the Hyper-diverse Mammalian Community of Sangay National Park in Ecuador

 

Coendou sangay Brito, 

in Brito​, Curay, León-Caldas, Lojan-Cueva, Ojala-Barbour, Pozo-Zamora, Simba, Tito, Vargas, Vega-Yánez et Batallas, 2026. 

Sangay Porcupine | Puerco espín de Sangay  ||  DOI:  doi.org/10.7717/peerj.21382

Abstract 

The tropical Andes harbor high levels of undocumented biodiversity, often hidden within complex ecological communities that require sustained sampling efforts to be fully characterized. Here, we describe a new species of porcupine of the genus Coendou, discovered within the hyper-diverse mammalian assemblage of Sangay National Park (Sangay) in Ecuador. The description is based on an adult specimen collected at 2,400 m on the eastern slopes of the Andes. Phylogenetic analyses using mitochondrial Cytochrome b (Cytb) place the new species as a distinct lineage within the Clade B (sensu (Voss, Hubbard & Jansa, 2013)), showing significant genetic divergence (p-distance > 6.0%) from its closest congeners, C. speratus, C. nycthemera and C. bicolor. Morphologically, Coendou sangay sp. nov. is diagnosed by its medium body size, a remarkably short tail (approx. 26% of head-and-body length), tricolored bristle-quills with brownish-red tips, and distinct cranial features, including a long nasal bone and a mesopterygoid fossa that does not reach the second upper molar. This discovery is contextualized within a comprehensive mammalian inventory of Sangay, compiled over 15 years of fieldwork. Despite an intensive sampling effort totaling 12,800 trap-nights and 2,400 camera-trap days, only a single specimen was obtained, highlighting the species status as a rare, canopy-dwelling specialist. We report 170 mammal species within the park, including 18 endemic and 35 threatened taxa. With a richness of 0.03 species per km2, Sangay ranks as the most mammal-diverse protected area per unit area in the Tropics. Our results demonstrate that intensive, long-term inventories are essential for identifying cryptic arboreal lineages that remain “invisible” to traditional terrestrial sampling. Finally, we emphasize the urgent need for conservation policies, including the strengthening of biological corridors and the limitation on road and mining expansion, to safeguard this high-elevation biodiversity hotspot.

Keywords: Eastern Andes, Cloud forest, Rare species, Biodiversity hotspot, Species delimitation

Systematic

Family Erethizontidae Bonaparte, 1845

Genus Coendou Lacépède, 1799

Coendou sangay new species. Brito

Coendou rufescens: Brito & Ojala-Barbour (2016), not Coendou rufescens (Gray, 1865)

Coendou rufescens: Batallas & Brito (2022), not Coendou rufescens (Gray, 1865)

Sangay Porcupine, Puerco espín de Sangay (in Spanish)

Diagnosis. Coendou sangay sp. nov. is distinguished from other species of the genus by its medium-sized body (HBL 460 mm) and very small tail (26% LT/HBL), absence of long fur, tricolored bristle-quills (with brownish red tips), spiny ventral fur, and a unique combination of cranial features, including a long nasal bone (35% LN/CIL), constricted maxillary bony bridge, and a mesopterygoid fossa that does not reach M2.

Coendou sangay sp. nov. (MECN 4343, holotype).
 (A) External appearance of the adult female alive in its natural habitat in the Sangay, Ecuador; (B) lateral and (C) posterior view of the revealing an aposematic coloration.

 Photographs by J. Brito.

Selected external and soft anatomical features of Coendou sangay sp. nov. (MECN 4343, holotype).
Ventral view of the hand (A), and of the foot (B); detail of the muzzle (C); perineal region (D), and ventral view of the tail (E).

 Abbreviations: a = anus, v = vagina. Photographs by J. Brito.

Etymology: This species is named in honor of Sangay National Park, which is the largest Andean national park in Ecuador. The park includes a large elevation gradient along the eastern slopes, or Eastern Cordillera, of the Andes and is recognized as a UNESCO World Heritage Site. The park gets its name from Sangay, one of Ecuador’s most active volcanoes, which is located within its boundaries.

Field expedition to Guabisai (A), Cubillines (B), and sampling and collecting in the area (C, D).

Photographs of J. Brito (A, C, D), and G. Pozo (B).

Jorge Brito​, Jenny Curay, Víctor León-Caldas, Pamela Lojan-Cueva, Reed Ojala-Barbour, Glenda Pozo-Zamora, Laura Simba, Paul Tito, Rocío Vargas, Mateo A. Vega-Yánez and Diego Batallas. 2026. Discovery of A New Species of Coendou (Rodentia: Erethizontidae) within the Hyper-diverse Mammalian Community of Sangay National Park in Ecuador. PeerJ. 14:e21382 DOI:  doi.org/10.7717/peerj.21382 [June 8, 2026]

[Paleontology • 2026] Polonolimulus zaleziankensis • A New Triassic austrolimulid from Poland presents insight into xiphosurid Evolution and Palaeobiogeography at the Dawn of the Mesozoic

 

Polonolimulus zaleziankensis 

Audycki​, Bicknell, Niedźwiedzki & De Baets, 2026 

 

 DOI: doi.org/10.7717/peerj.20950 

Reconstruction by Jonatan Audycki

Abstract 

Xiphosurids are aquatic chelicerates widely viewed as examples of so-called ‘living fossils’ due to their apparent morphological conservatism and limited diversity since at least the Jurassic. However, earlier representatives were much more diverse and morphologically disparate. Particularly striking are hypertrophied genal spines and reduced thoracetrons of the Triassic austrolimulids, possibly related to their colonization of brackish or freshwater habitats. Here we describe Polonolimulus zaleziankensis gen. et sp. nov., a new austrolimulid genus from the Early Triassic of Holy Cross Mountains, Poland. Geometric morphometric analysis positions the new find among the morphologically most ‘extreme’ austrolimulids, extending the geographic range of those forms to Central Europe. A palaeobiogeographic reconstruction of Triassic xiphosurids reveals their surprisingly wide distribution already in Early Triassic, suggesting either an earlier dispersal in the Late Permian or a rapid diversification in the earliest Triassic. The reconstruction of most austrolimulid occurrences within or proximal to the shallow marine areas casts doubts on the hypothesis they inhabited fully freshwater palaeonvironments, which should be reinvestigated in the future. The new material further adds to the growing understanding of xiphosurid diversity and evolution in the early Mesozoic.

 

Keywords: Limulus, Horseshoe crab, Arthropoda, Buntsandstein, Holy Cross Mountains

Polonolimulus zaleziankensis gen. et sp. nov. 
The rock slab bearing Muz. PGI 1808.II.10 and another xiphosurid fossil.
(A) The upper surface of the rock slab with Muz. PGI 1808.II.10 preserved as a concave natural mould. (B) The lower surface of the rock slab with the uncertain convex horseshoe crab-shaped structure, considered a possible trace fossil (see ‘Remarks’ for further discussion).
(C) Close-up of Muz. PGI 1808.II.10 (D) Close-up of the convex structure on the lower surface coated with ammonium chloride sublimate. Scale bars: (A, B) 50 mm, (C, D) 20 mm. Photo credit: Jonatan Audycki.

Polonolimulus zaleziankensis gen. et sp. nov.

Idealized reconstruction of Polonolimulus zaleziankensis gen. et sp. nov.

Reconstruction by Jonatan Audycki.

Palaeobiogeography of Triassic horseshoe crabs. Palaeogeography of the world is reconstructed at 245 Ma (Anisian, Middle Triassic) and displayed using Mollweide projection, with a close-up of the Central European Basin System. The extents of shallow seas (light blue), landmasses (pale yellow) and mountain ranges (orange) are reconstructed based on Cao et al. (2017). Symbols represent Triassic localities that have yielded horseshoe crab fossils, their ages, and taxonomic assignment. The palaecoordinates of the xiphosurid localities are also reconstructed at 245 Ma for consistency. Simplified reconstructions of austrolimulids are displayed for context and comparison: 1–Polonolimulus zaleziankensis from the Lower Triassic (uppermost Induan/lowermost Olenekian) Zalezianka-Gózd locality, Poland; 2–Psammolimulus gottingensis from the Lower Triassic (Olenekian) Solling Formation, Germany; 3–Batracholimulus fuchsbergensis from the Upper Triassic (Norian/Rhaetian boundary) Exter Formation, Germany; 4–Attenborolimulus superspinosus from the Lower Triassic (upper Olenekian) Petropavlovka Formation, Russia; 5–Vaderlimulus tricki from the Lower Triassic (lower Spathian, Olenekian) Thaynes Group, USA; 6–Austrolimulus fletcheri from the Middle Triassic (lower Anisian) Beacon Hill Quarry, Hawkesbury Sandstone, Australia; 7–Dubbolimulus peetae from the Middle Triassic (lower Anisian) Ballimore Formation, Australia; 8–Tasmaniolimulus patersoni from the Lower Triassic (lower Induan) Jackey Shale, Tasmania (Australia). Since the investigated xiphosurid localities differ stratigraphically, their geographical position relative to continental boundaries and shallow seashores are approximated. The display window on the map showing close-up boundaries is not square due to employed map projection.

 

Jonatan Audycki​, Russell D.C. Bicknell, Grzegorz Niedźwiedzki, Kenneth De Baets. 2026.  2026. A New Triassic austrolimulid from Poland presents insight into xiphosurid Evolution and Palaeobiogeography at the Dawn of the Mesozoic. PeerJ. 14:e20950. DOI: doi.org/10.7717/peerj.20950 [2026-03-25]

 x.com/IBE_Warszawa/status/2036854712750780757

[Herpetology • 2026] Nyctibatrachus kali • Hiding in plain sight: A New Species of Nyctibatrachus (Anura: Nyctibatrachidae) from the central Western Ghats, India

Nyctibatrachus kali 

Aravind, Ramesh, Naik, Gururaja & Priti, 2026

DOI: doi.org/10.7717/peerj.20895

Abstract 

Frogs belonging to the genus Nyctibatrachus are endemic to the Western Ghats biodiversity hotspot. They are the second most speciose frogs in the Western Ghats, with 70% of the species having narrow distribution ranges. They are also highly cryptic in nature. In this study, we describe a new species of Nyctibatrachus frog from the central Western Ghats of India. Nyctibatrachus kali sp. nov. is described from the Kali River basin of North Karnataka. The new species is distinguishable from all 34 currently recognised Nyctibatrachus species by a combination of morphological, acoustic and phylogenetic analyses. Molecular phylogeny based on two mitochondrial genes (16S rRNA and ND1) reveals that it belongs to the N. sanctipalustris clade. Based on the analysis of 16S rRNA, Nyctibatrachus kali sp. nov. shows genetic divergence >5% with its congeners, and based on the analysis of ND1, Nyctibatrachus kali sp. nov. shows genetic divergence >10% with its congeners. The bioacoustics analyses indicated that the new species differed from their closest congeners based on the dominant frequency of the advertisement calls and the number of notes in each call. For the first time, we observed two distinct advertisement call categories–call notes with low and high dominant frequency in Nyctibatrachus kali sp. nov. and its congeners. Our study adds to the rich diversity of frogs from the Western Ghats of India.

Keywords: Bioacoustics, Biodiversity, Cryptic species, Endemic frogs, Freshwater ecosystem, Night frogs

Habitus of holotype (BNHS 6831) of Nyctibatrachus kali sp. nov.
 (A) Live individual of holotype; (B) Slow flowing stream habitat of the holotype with female and a clutch of eggs; (C) Dorsal view; (D) Ventral view; (E): Lateral profile of head and trunk; (F): Ventral view of hand; (G): Ventral view of foot; (H): third finger disc without dorso-terminal groove; (I): fourth toe disc with dorso-terminal groove cover notched distally; (J): Schematic view of webbing in hindlimb (black lines represents toes, curved black lines represents webbing, blue circles represents subarticular tubercle and orange circles represents toe discs.).

 Nyctibatrachus kali sp. nov. 

Diagnosis: Based on molecular phylogenetic analysis, Nyctibatrachus kali sp. nov. belongs to the N. sanctipalustris clade (Fig. 4) and is a sister lineage to N. dattatreyaensis. Hence, we compared Nyctibatrachus kali sp. nov. (both ♂ and ♀ individuals of type specimens) with all the species belonging to the N. sanctipalustris clade (both ♂ and ♀ individuals of type specimens), i.e., N. dattatreyaensis; N. karnatakaensis; N. kumbara; N. sanctipalustris; N. shiradi, N. tunga and N. vrijeuni.

...

Etymology: We name the species as Kali, the river at which the type locality of the species located. The specific epithet is an invariable noun in apposition.

 

C. K. Aravind, Badiger Ramesh, Chandrakanth Rukkappa Naik, K. V. Gururaja and Hebbar Priti. 2026. Hiding in plain sight: Description of A New Species of Nyctibatrachus (Amphibia, Anura, Nyctibatrachidae) from the central Western Ghats, India. PeerJ. 14:e20895 . DOI: doi.org/10.7717/peerj.20895 [2026-03-27]

[Paleontology • 2026] Indosinosuchus peninsularensis • A new teleosaurid (Crocodylomorpha: Thalattosuchia) from the Sibumasu Terrane of Southeast Asia and A Taxonomic Reassessment of Indosinosuchus

 

Indosinosuchus peninsularensis 

Lauprasert, Nilpanapan, Martin, Claude, Kamonlak Wongko, Kantanat Trakunweerayut, Dobutr, Manitkoon, Bhuttarach & Nonsrirach, 2026

DOI: doi.org/10.7717/peerj.20944  

 facebook.com/Lauprasert

Abstract 

We describe teleosaurid remains from the Middle to Upper Jurassic Khlong Min Formation at Ban Nam Pun in southern Thailand and define Indosinosuchus peninsularensis sp. nov. This new species is diagnosed by a unique combination of cranial and postcranial features, including the nasal reaching anteriorly at the level of the 18th maxillary alveolus, absence of an incisive foramen, oval-shaped external nares, and broad ornamented osteoderms. Phylogenetic analysis positions I. peninsularensis within a polytomy alongside Mystriosaurus laurillardi and other Asian teleosaurids, supporting a monophyletic Teleosauroidea. In addition, the revision of Indosinosuchus kalasinensis as a junior synonym of I. potamosiamensis also strengthens the taxonomic framework of the genus Indosinosuchus. Indosinosuchus peninsularensis sp. nov., discovered in a low-energy lagoonal environment, offers significant insights on the ecological preferences of teleosaurids. In contrast to the fluvially deposited Phu Kradung Formation of northeastern Thailand, the lagoonal and marginal marine sediments of the Khlong Min Formation are considered indicative of a broad spectrum of habitat occupation by Asian teleosauroids. Based on these observations, a high degree of ecological plasticity has been inferred for Thai teleosaurids, and their extensive dispersal across both the Sibumasu and Indochina terranes during the Middle to Late Jurassic has been further substantiated. The recognition of I. peninsularensis sp. nov. contributes to our understanding of teleosaurid diversity and paleobiogeography in Southeast Asia.

Keywords: Indosinosuchus, Khlong Min Formation, Sibumasu, Phu Kradung Formation, Indochina

Indosinosuchus peninsularensis sp. nov. from the Khong Min Formation, Ban Nam Pun, southern Thailand. Photographs and interpretive drawings of Indosinosuchus peninsularensis sp. nov. from the Khong Min Formation, Ban Nam Pun, Nakhon Si Thammarat Province, southern Thailand.
PRC-205: anterior rostrum in dorsal view (A, B) and dorsal vertebrae in ventral view (C, D). PRC-206: osteoderms and dorsal vertebrae in dorsal view (E, F) and ventral view (G, H).

Abbreviations: dv, dorsal vertebrae; en, external nares; mx, maxilla; n, nasal; ost, osteoderm; pmx, premaxilla.

CROCODYLOMORPHA Hay, 1930

THALATTOSUCHIA Fraas, 1901

NEOTHALATTOSUCHIA Young et al., 2024a; Young et al., 2024b

TELEOSAUROIDEA Delfino & Dal Sasso, 2006

TELEOSAURIDAE Geoffroy Saint-Hilaire, 1831

Genus Indosinosuchus Martin et al., 2019

Indosinosuchus peninsularensis 

Holotype: PRC 205 and PRC 206, comprising an anterior portion of the rostrum, osteoderms, and dorsal vertebrae.

Type locality: Ban Nam Pun, Bang Khan District, Nakhon Si Thammarat Province, southern Thailand.

Stratigraphic occurrence: Lower part of the Khlong Min Formation, Thung Yai Group, late Middle Jurassic to early Late Jurassic.

Diagnosis. Indosinosuchus peninsularensis, PRC 205, is characterized by the following combination of characters (autapomorphies denoted with*): (1) four premaxillary alveoli; (2) moderately laterally expanded premaxilla with subequal length and width, producing a broad yet unflared outline; (3) margin of premaxillary-maxillary suture is concave between the 4th premaxillary –1st maxillary alveoli; (4) the external narial opening is subcircular or slightly ‘8-shaped’ in dorsal view; (5) absence of incisive foramen at medial contact of premaxillae*; (6) anterior tip of nasals reaching the level of the 18th maxillary alveolus*.

Locality, lithostratigraphy, and petrographic characteristics of the fossiliferous limestone within the Khlong Min Formation at Ban Nam Pun, southern Thailand.
(A) Tectonic subdivision map of Thailand (modified after Udchachon et al., 2022), illustrating the distribution of Jurassic sedimentary rock units (based on Meesook & Saengsrichan, 2011). The Khlong Min Formation, including the Ban Nam Pun locality, is situated within the Sibumasu Terrane, whereas the Phu Kradung Formation and its equivalents are located within the Indochina and Sukhothai Terranes. (B) Simplified geological map of the Krabi–Khlong Thom–Trang region (adapted from Thailand Department of Mineral Resources, 1999; Meesook & Saengsrichan, 2011), with the study site marked by a red star.
(C) Field photograph of the fossiliferous limestone outcrop intercalated with mudstone. The rock hammer (circled) is 30 cm in length for scale. (D–F) Close-up view of fossiliferous limestone rich in bivalves, (D) Modiolus sp. assemblage, (E) Actinostreon sp. (F) Protocardia sp. (G) MF1: Bioclast wackestone characterized by shell fragments, benthic foraminifera (f), and peloids (p). The yellow arrow indicates a bivalve shell with geopetal fabric: the lower portion infilled with micritic matrix and peloids, and the upper portion filled with sparry calcite cement. (H) MF2: Bioclast-peloidal packstone to grainstone, dominated by peloids (p) and benthic foraminifers (f) with minor ostracod shells (o).

 Komsorn Lauprasert, Apirut Nilpanapan, Jeremy E. Martin, Julien Claude, Kamonlak Wongko, Kantanat Trakunweerayut, Nuntida Dobutr, Sita Manitkoon, Supanut Bhuttarach and Thanit Nonsrirach. 2026. A new teleosaurid (Crocodylomorpha, Thalattosuchia) from the Sibumasu Terrane of Southeast Asia and A Taxonomic Reassessment of Indosinosuchus. PeerJ. 14:e20944. DOI: doi.org/10.7717/peerj.20944 [2026-03-20]

 facebook.com/Lauprasert/posts/10164083724222162

 

[Herpetology • 2026] Luperosaurus alvarezi • A New Species of fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines

Luperosaurus alvarezi Meneses​ & Brown, 2026
Luperosaurus cumingii Gray, 1845

DOI: doi.org/10.7717/peerj.20504

Abstract 

We describe a new species of Luperosaurus based on two specimens collected on Sibuyan Island, Romblon Province, central Philippines. The new species is phenotypically similar to L. cumingii (southern Luzon), L. angliit (northern Luzon), L. corfieldi (from Panay and Negros islands), and L. macgregori (the Babuyan and Batanes island groups), but differs from these closely related congeners and all other known Luperosaurus by a combination of discrete morphological characters. Extensive molecular divergence from all closely related species for which genetic data are available supports the new species as a distinct lineage. Its distribution is geographically isolated from congeners, restricted to a permanently isolated deep-water island. The new species’ extremely limited geographic range contributes to the recognition of the remaining forests of the central Philippine Romblon Island Group as a fundamental conservation priority for the archipelago.

Squamata Oppel, 1811

Gekkonidae Gray, 1825

Luperosaurus Gray, 1845

Photos in life of Luperosaurus alvarezi sp. nov. (holotype and paratype) and Luperosaurus cumingii.
Adult specimens of Luperosaurus alvarezi sp. nov. (left to right: holotype: PNM 9866: adult male; SVL 66.1 mm and paratype: UPLB-MNH-Z-NS 4622 (CGM 989); adult female; SVL 78.3 mm) from Mt. Guiting-Guiting Natural Park, Romblon Province, Sibuyan Island.
Adult female L . cumingii (TNHC 61910; SVL 75.2 mm) from Mt. Malinao, Albay Province, Bicol Peninsula, Luzon Island. Note differences: L. cumingii has prominent spinose ventrolateral tail tubercles and heterogeneous nuchal and body tubercles (bottom left image).

Photographs were taken by Camila G. Meneses and Rafe M. Brown.

Luperosaurus alvarezi sp. nov.

  Diagnosis. Luperosaurus alvarezi sp. nov. is diagnosed from congeners by possession of the following combination of characters: (1) bright yellow superciliaries and circumorbitals (Fig. 4); (2) light gray iris (Fig. 4); (3) precloacofemorals 22,22 (Fig. 5B; Fig. S1); (4) five scales contacting nostrils (Figs. 6A, 6B, 6D); (5) Head length/width 1.4,1.5; (6) presence of few, enlarged, flat to convex ornamental scales on margin of anterior forelimb expansion; (7) presence of elliptical, small, and oblique auricular opening; (8) dorsal body tubercles absent; (9) ventrolateral body tubercles absent; (10) presence of few, flat, and enlarged scales on caudal edges of tail whorls; (11) longitudinal midventrals 108, 110; (12) anterior hindlimbs expansions reduced to moderate folds. The condition of five scales contacting the nostrils, head length-to-width ratio, absence of dorsal and ventrolateral body tubercles, and presence of a few flat, enlarged scales on the caudal edges of tail whorls are shared among congeners but are diagnostic for Luperosaurus alvarezi sp. nov. in combination with other characters, distinguishing it from the morphologically similar L. corfieldi and L. cumingii, with which it shares certain intermediate external similarities. Table 1 presents a summary of the distribution of diagnostic character states among Philippine Luperosaurus.

Etymology: We are pleased to name the new species after our dear friend, frequent field companion and collaborator, the late James Alvarez (1991–2018), who lost his life while conducting bat research in the Philippines’ highest mountain, Mt. Apo, on December 8, 2018. We derived the specific epithet, a patronym, in the genitive singular, in recognition to Mr. Alvarez’s scientific contributions and demonstrated personal commitment to furthering knowledge of the natural history of Philippine chiropterans—in particular, the ecology and diversity of bats in Sibuyan Island.

Microhabitat of Luperosaurus alvarezi sp. nov. on Sibuyan Island, Philippines.
(A) Habitat characteristics of the type locality of Luperosaurus alvarezi sp. nov. at Mt. Guiting-Guiting Natural Park, Sibuyan Island, Philippines, and (B) Appearance of the microhabitat of the new species of Fringed Forest Gecko, Luperosaurus alvarezi sp. nov., on the Gaong River.

Photographs were taken by Camila G. Meneses.

 

Camila G. Meneses​ and Rafe M. Brown. 2026. A New Species of fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines. PeerJ. 14:e20504. DOI: doi.org/10.7717/peerj.20504 [March 4, 2026]

[Botany • 2026] Nymphanthus belliflorus (Phyllanthaceae) • A New Species from Thailand

 

Nymphanthus belliflorus P. Sukkharom, Chantar. & Pornp., 

in Sukkharom, Chantaranothai et Pornpongrungrueng, 2026. 

ว่านธรณีสารเล็ก  ||  DOI: doi.org/10.7717/peerj.20559 

Abstract

Nymphanthus belliflorus, a newly described species from the northeastern part of Thailand, is the most similar to N. chantaranothaii, N. glaucescens and N. huamotensis in having staminate flowers with four sepals bearing long-fimbriate margins and the pistillate flowers composed of 5–6 sepals with long-fimbriate margins. However, it is distinguished by its swollen stem base, young branchlets that are glabrous, disc glands of staminate flowers that are obdeltoid and yellow-reddish in color, long pedicel of pistillate flowers (3.2–4.8 cm long) and fruits (3.5–5.5 cm long). The description, distribution, ecological information and provisional conservation status are provided.

Keywords: Eriococcus, Morphology, Phyllantheae, Phyllanthus, Taxonomy, Section Nymphanthus

Nymphanthus belliflorus P. Sukkharom, Chantar. & Pornp., sp. nov.
 (A) Habit. (B) Leaf (adaxial side). (C) Leaf (abaxial side). (D) Stipule. (E) Staminate flower. (F) Pistillate flower. (G) Mature capsule.

drawn by Piya Sukkharom.

Nymphanthus belliflorus.
(A) Habit. (B) Staminate flowers. (C) Pistillate flower. (D) Mature capsule. (E) Swollen stem base. (A) & (E) photos by Piya Sukkharom, (B–D) photos by Silakan Khunnok.

Nymphanthus belliflorus P. Sukkharom, Chantar. & Pornp., sp. nov. 

Diagnosis. Nymphanthus belliflorus is distinguished from other species of Nymphanthus by a combination of swollen stem base, long-fimbriate sepal margins in both staminate and pistillate flowers, obdeltoid, yellow to reddish disc glands in staminate flowers, and long pedicels in pistillate flowers and fruits (3.2–4.8 cm long and 3.5–5.5 cm long, respectively).

Etymology. The specific epithet refers to the beautiful flowers of this species.

Vernacular name. Wan thorani san lek (proposed here).

Distribution. Khon Kaen and Sakon Nakhon Provinces in the northeast of Thailand.

Ecology. Nymphanthus belliflorus grows on sandy soil with organic matter found in the ecotone between mixed deciduous and dry dipterocarp forest, at 240–285 m elevation.

Piya Sukkharom, Pranom Chantaranothai and Pimwadee Pornpongrungrueng​. 2026. Nymphanthus belliflorus (Phyllanthaceae), A New Species from Thailand. PeerJ. 14:e20559. DOI: doi.org/10.7717/peerj.20559 [January 21, 2026]

[Herpetology • 2026] Leptobrachium mechuka & L. somani • Abundance in Secret: A Review of the Genus Leptobrachium (Anura: Megophryidae) in India, with Descriptions of Two New Species

Leptobrachium mechuka
 Leptobrachium somani 

  Sarmah, Garg, Tajo, Upadhyaya, Hanken & Biju, 2026 

  

DOI: doi.org/10.7717/peerj.20397 

Abstract 

Of the 39 currently recognized species in the Slender Armed Frog genus Leptobrachium, four are reported from India, Leptobrachium aryatium, L. bompu, L. smithi, and L. sylheticum. Based on new collections, we review these reported species by integrating molecular, morphological, and behavioral data. Our comparative analyses of external and internal morphology as well as molecular data and acoustic properties reveal two new species-level lineages from the Lower Dibang Valley and Shi Yomi districts of Arunachal Pradesh, India, which we describe here as new species. Phylogenetically, Leptobrachium mechuka sp. nov. and Leptobrachium somani sp. nov. are members of the L. bompu species group, but they are distinct from L. bompu sensu stricto by DNA sequence divergence in the 16S mitochondrial rRNA gene of 3.6–4.2% and 4.5–4.7%, respectively. A population previously identified as L. cf. bompu from Medog County, China, is also assignable to Leptobrachium mechuka sp. nov. Each new species is distinguished from congeners by a combination of diagnostic morphological characters, including in the case of Leptobrachium somani sp. nov., a unique advertisement call comprising two distinct call types; unicolored silvery white iris; moderately large webbing between toes; and ventral coloration. Leptobrachium mechuka sp. nov. on the other hand, is distinguishable by its head length equal to width; nostril equidistant from the snout tip and the eye; internarial distance equal to the distances from nostril to eye and from nostril to snout tip; distance from the tip of inner metatarsal tubercle to the tip of first toe shorter than the length of inner metatarsal tubercle itself; and frontoparietals separated at the midline by a moderate fontanelle. Analyses of multiple new populations representing members of the L. smithi group reveal that L. smithi is absent from the Indian fauna; all previous records attributed to this species from India instead represent L. aryatium or L. sylheticum. These discoveries highlight the prevalence of taxonomic misidentifications in the absence of detailed systematic studies as well as the underestimation of diversity in the genus Leptobrachium, not only from India but across its known range. Our results underscore the need for dedicated surveys that document amphibian diversity in underexplored regions of Northeast India.

Keywords: Amphibia, Arunachal Pradesh, Bioacoustics, Cranial osteology, Integrative taxonomy, Leptobrachium bompu group, Leptobrachium smithi group, Mitochondrial phylogeny, Northeast India, Tadpoles 

Phylogenetic relationships of the genus Leptobrachium and geographical distribution of species in India.

Geographical distributions of five Leptobrachium species herein recognized to occur in India.

Distribution of Leptobrachium bompu and L. smithi species groups in South and Southeast Asia.

Holotype and paratype of Leptobrachium mechuka sp. nov. in life.
 (A–J) Holotype ZSI A16315: (A) Dorsolateral view. (B) Dorsal view. (C) Ventral view. (D) Lateral view. (E) Posterior view of thighs. (F) Dorsal view of thighs. (G) Ventral view of hand. (H) Enlarged view of palmar tubercles on hand. (I) Ventral view of foot. (J) Dorsal view of foot. (K) Referred specimen (SDBDU 2025.6768) Dorsolateral view. (L, M) Paratype (ZSI A16316). (L) Dorsolateral view. (M) Enlarged view of eye. Photographs: T. Tajo.

Holotype and paratypes of Leptobrachium somani sp. nov. in life.
 (A–D) Dorsolateral view: (A) Paratype (ZSI A16335). (B) Paratype (ZSI A16336). (C) Referred specimen (SDBDU 2025.6773). (D) Holotype (ZSI A16333). (E–G) Paratype (ZSI A16336): (E) Frontal view. (F) Lateral view of head. (G) Enlarged view of eye. Photographs: S.D. Biju.

Leptobrachium mechuka sp. nov. 

 Leptobrachium somani sp. nov.,

 

 

A.N. Dikshit Akalabya Sarmah, Sonali Garg, Tage Tajo, Radhakrishna Upadhyaya K., James Hanken and S.D. Biju​. 2026. Abundance in Secret: A Review of the Genus Leptobrachium (Anura, Megophryidae) in India, with Descriptions of Two New Species. PeerJ. 14:e20397. DOI: doi.org/10.7717/peerj.20397 [January 9, 2026]

[Mammalogy • 2026] Oreoryzomys jumandi, O. balneator, O. hesperus, ... • Mountains of Diversity: A Systematic Revision of the Andean Rodent Genus Oreoryzomys (Rodentia: Cricetidae: Sigmodontinae)

 

(A-E) Oreoryzomys balneator (Thomas, 1900);
(F-J) O. hesperus (Anthony, 1924);
 (K-O) Oreoryzomys jumandi Brito, Vargas, García, Tinoco & Pardiñas, 

in Brito​, Vargas, Tinoco, García, Carrión-Olmedo, Koch, Wistuba, Nivelo-Villavicencio et Pardiñas. 2026. 

 DOI: doi.org/10.7717/peerj.20515

Abstract

The until recently monotypic cricetid genus Oreoryzomys inhabits piedmont and cloud forests, primarily in eastern Ecuador and northwestern Peru. Erected following the taxonomic revision of a polytypic Oryzomys complex two decades ago, Oreoryzomys has remained poorly understood, with most references limited to the original descriptions of its type species (O. balneator) and a subspecies (O. b. hesperus). Here, we present an integrative taxonomic revision of the genus, based on new field collections and comprehensive museum-based analyses. Phylogenetic reconstructions from mitochondrial and nuclear gene sequences, combined with morphometric and qualitative morphological data, support the recognition of three species: (1) a redescribed O. balneator from central-eastern Ecuador; (2) O. hesperus, elevated to full species rank based on topotypic material; and (3) a new species from populations of the Quijos River Valley, northeastern Ecuador. This revision triples the known species diversity of Oreoryzomys and highlights the genus as a notable radiation of small-bodied oryzomyines adapted to Andean environments. Our findings emphasize the need for systematic revisions of other poorly known Andean rodents to better reveal the hidden diversity of cricetids and the role of the Andes in shaping Neotropical biodiversity.

Keywords: Andes, Ecuador, New species, Oreoryzomys balneator, Oreoryzomys hesperus, Oryzomyini, Peru

 

External appearance of the three Oreoryzomys species (left panels) and details of their feet and hands (right panels).
Top row: (A) live lateral view (O. balneator, MECN 5815); (B–C) plantar and dorsal views of foot; (D–E) palmar and dorsal views of hand (MECN 6140).
Middle row: (F) live lateral view (O. a. hesperus, MECN 4789); (G–H) plantar and dorsal views of foot; (I–J) palmar and dorsal views of hand.
Bottom row: (K) live lateral view (Oreoryzomys jumandi sp. nov., MECN 8278, holotype); (L–M) plantar and dorsal views of foot; (N–O) palmar and dorsal views of hand.

Scale = 10 mm. Photographs (A–J, L–O) by J Brito; (K) by R Wistuba.

Oreoryzomys jumandi new species. Brito, Vargas, García, Tinoco & Pardiñas

 

Jumandi Mountain Mouse, 

Ratón montano de Jumandi (in Spanish)

 

Diagnosis: A species of Oreoryzomys distinguished by the following combination of characters: incisive foramina short, not reaching the anterior margin of M1 (Fig. 6F); frontoparietal (coronal) suture distinctly V-shaped (Fig. 6E); stapedial process of the auditory bulla elongate and pointed, projecting beyond the posterior margin of the alisphenoid (Fig. 9F); median lacerate foramen broad and positioned at a distance from the bulla; M3 with the hypoflexus shallow, forming a lake-like structure; and m2 with a long mesolophid fused to the mesostyle (Fig. 11C).

 

Etymology: Named in honor of Jumandi, a Quijo warrior who led the first indigenous uprising against Spanish conquistadors in the Americas on 29 November 1578 (Santos-Granero, 1992). In recognition of his historical significance, Jumandi was officially declared a National Hero by the Asamblea Nacional del Ecuador in November 2011.

Jorge Brito​, Rocío Vargas, Nicolás Tinoco, Rubí García, Julio C. Carrión-Olmedo, Claudia Koch, Ricarda Wistuba, Carlos Nivelo-Villavicencio and Ulyses F.J. Pardiñas. 2026. Mountains of Diversity: A Systematic Revision of the Andean Rodent Genus Oreoryzomys (Cricetidae: Sigmodontinae). PeerJ. 14:e20515. DOI: doi.org/10.7717/peerj.20515 [January 9, 2026]

 

[Herpetology • 2025] Cryptomantis subgenus nov. & Pristimantis paganus • Vast Cryptic Diversity in Direct-developing Frogs Pristimantis (Anura: Strabomantidae): A New Subgenus and the Description of A New Species from the eastern Andes of Ecuador

 

Pristimantis paganus  

Loza-Carvajal, Yánez-Muñoz, Quilumbaquin & Ortega-Andrade, 2025

 

Amazonian pagan rainfrog| Cutín pagano Amazónico  ||  DOI: doi.org/10.7717/peerj.20512

Abstract 

Pristimantis, a genus of direct-developing frogs within the family Strabomantidae, comprises 617 recognized species, making it the most species-rich genus of vertebrates worldwide. This group include 264 described (43% of the world) species in Ecuador, being one of the countries in the region with the highest rate of species description, greatest diversity and endemism. In this study, we analyze the phylogenetic position and describe a new Pristimantis species from the Colonso Chalupas Biological Reserve and Llanganates National Park in northeastern Ecuador, using phylogenetic, genetic, morphological, and geographic evidence. Additionally, we propose a new subgenus within Pristimantis that includes the Pristimantis prolatus and Pristimantis bicantus species groups. Our results indicate that the new species and related species form a well-supported group with significant genetic divergence based on the 16S rRNA gene (average uncorrected p-distance = 2.8–7.5%), within the Pristimantis bicantus species group. Morphologically, the new species is characterized by a black to dark-gray dorsum and marbled venter (less intense or brown in males), being endemic to the Guacamayos mountain range and the Llanganates region in the northeastern Andean foothills of Ecuador. We emphasize the importance of including topotypic specimens to analyze and compare species groups to delimiting species, like Pristimantis.

 

Keywords: Integrative taxonomy, Cryptic diversity, Pristimantis paganus sp. nov., Pristimantis prolatus group, Pristimantis bicantus group, Cryptomantis gen. nov.

Pristimantis paganus sp. nov. 
Holotype in life DHMECN 16810, adult female, SVL = 27.2 mm.
(A) Dorsal view; (B) frontal view; (C) lateral view; (D) ventral view. Photographs by Mario H. Yánez Muñoz.

Pristimantis paganus sp. nov.

Suggested common English name: Amazonian pagan rainfrog

Common name in Spanish: Cutín pagano Amazónico.

Diagnosis. Pristimantis paganus sp. nov. (Figs. 2–7) is a member of the subgenus Cryptomantis and P. bicantus species group, characterized by the following combination of characters: (1) dorsal skin finely granular with dorso-laterally aligned flattened warts, areolate venter, discoidal fold present and visible posteriorly, dorsolateral folds weak and discontinuous in females, continuous in males; scapular W-shaped fold in males; (2) tympanic membrane and tympanic annulus present, round, horizontal diameter of tympanum equal to 38% of eye diameter, antero-dorsal margin with a supratympanic fold and large subconical postrictal tubercles; (3) snout short, subacuminate in dorsal view, rounded in profile with slightly flared lips; (4) upper eyelid with at least three to four large rounded tubercles surrounded by several small rounded tubercles, two subconical tubercles behind each eye; no cranial crest; (5) dentigerous processes of vomers, oblique in outline each process with 3–8 teeth; (6) vocal slits absent; no nuptial pad and no vocal sac; (7) Finger I shorter than Finger II; broad, expanded disks dilated with circummarginal grooves; (8) fingers with thin lateral cutaneous fringes; (9) subarticular tubercles, present, prominent; hyperdistal subarticular tubercle, present; ulnar tubercles absent; (10) heel with one subconical tubercle; outer edge with two flattened tubercles, tarsal fold absent; (11) inner metatarsal tubercle oval in females 3 times larger than rounded outer metatarsal tubercle; supernumerary tubercles absent; (12) toes with thin lateral fringes present, interdigital membrane absent, Toe V longer than Toe III; (13) The distinctive coloration of females, characterized by a uniformly black dorsum and black markings on a cream to pinkish-cream background on the flanks, belly, and throat, distinguishes this species from its congeners and other Pristimantis species inhabiting the eastern montane forests of Ecuador; (14) adult males, SVL = 17.20–21.5 mm (mean = 19.6, n = 13), females SVL= 24.8–29.8 mm (mean = 29.6 mm, n = 6), (Tables 2, 3, S3).

Etymology. The specific epithet is from the Latin word “paganus”, an adjective derived from “pagus”, which refers to the inhabitants of the forest or village, far from civilization and towns, referring to the remote and unexplored sites where this species inhabits, in the montane cloud forests at the Colonso Chalupas Biological Reserve and Llanganates National Park, northeastern flanks of the Andes in Ecuador.

Habitat and specimens of Pristimantis paganus sp. nov.
(A) Cloud forest with epiphytic plants, type locality, Colonso Chalupas Biological Reserve; (B) female, DHMECN 19962;
(C) paratype, male, DHMECN 15602; (D) paratype, adult female, DHMECN 17222.

Photographs: Jorge Brito (A), Keyko D. Loza-Carvajal (B), H. Mauricio Ortega-Andrade (C), Zane Libke (D).

Representative species of the subgenus Cryptomantis.
Subclade A-Pristimantis prolatus species group: (A) Pristimantis ganonotus DHMECN 16961, Colonso Chalupas Reserve, Napo; (B) P. burtoniorum DHMECN 14479, Paratype, Mayordomo Reserve, Tungurahua; (C) P. prolatus DHMECN 11564, Topotype, Río El Reventador, Sucumbíos;
(D) P. c.sp. 1, DHMECN 15674, Colonso Chalupas Reserve, Napo.
Subclade B-Pristimantis bicantus species group: (E) P. c.sp. 2, QCAZ 70020, Llanganates National Park, Napo; (F) P. marcoreyesi, DHMECN 13833, Tungurahua volcano, Tungurahua; (G) P. paganus sp. nov. DHMECN 15606, Colonso Chalupas Reserve, Napo;
(H) P. tungurahua, DHMECN 14428, Vizcaya Reserve, Tungurahua; (I) P. sacharuna, QCAZ 52496, Zúñag Reserve, Tungurahua; (J) P. c.sp. 3, QCAZ 51553, San Antonio de Juval, Cañar;
(K) P. nelsongalloi, DHMECN 5223, Zúñag Reserve, Tungurahua; (L) P. bicantus, DHMECN 12359, El Reventador, Sucumbíos; (M) P. c.sp. 5, QCAZ 52489, Sangay National Park, Morona Santiago.

Photo credit: Gustavo Pazmiño, Bioweb (E); Santiago Ron, Bioweb (I), Bioweb (J, M); Keyko D. Loza, Carvajal (A); Mario H. Yánez Muñoz (B, C, F, H, K, L); H. Mauricio Ortega-Andrade (D, G).

Conclusions: 

We described a new species, Pristimantis paganus, from the Colonso Chalupas Biological Reserve and Llanganates National Park, northeastern Ecuador. Furthermore, we define a new subgenus, Cryptomantis, within Pristimantis that includes the Pristimantis prolatus and Pristimantis bicantus species groups. Our results indicate at least five Candidate species within Cryptomantis. We emphasize the importance of including topotypic specimens to analyze and compare specios groups to delimiting species, like Pristimantis.

 

Keyko D. Loza-Carvajal, Mario H. Yánez-Muñoz, Walter Quilumbaquin and H. Mauricio Ortega-Andrade​. 2025. Vast Cryptic Diversity in Direct-developing Frogs Pristimantis (Anura: Strabomantidae): A New Subgenus and the Description of A New Species from the eastern Andes of Ecuador. PeerJ. 13:e20512. DOI: doi.org/10.7717/peerj.20512 [December 17, 2025]