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Pantepui s.l. is a remote, biodiverse region of ~400 000 km2 containing at least five endemic reptile genera and a number of ancient vertebrate lineages. Here, we describe an additional endemic snake genus and species, Paikwaophis kruki gen. nov. sp. nov. (Dipsadidae: Xenodontinae), recently collected in the Pantepui cloud forest that sits at the base of the steep cliffs of Roraima-tepui and Wei-Assipu-tepui (table mountains of the Eastern Tepui Chain) in Guyana, South America. Multilocus molecular data strongly support Paikwaophis gen. nov. to be most closely related to Xenopholis Peters, 1869, although both genera are strikingly different morphologically. Osteological and other phenotypic data suggest that Paikwaophis is semi-fossorial; its diet includes minute lizards. Paikwaophis is currently the only known Pantepui endemic snake genus. The immature female holotype is the only known specimen. [ABSTRACT FROM AUTHOR]

The hemiphractid frog genus Stefania is one of the many ancient (near-) endemic lineages of vertebrates inhabiting the biodiverse Pantepui biogeographical region in the Guiana Shield Highlands of northern South America—the famous "Lost World" of Arthur Conan Doyle. Previous molecular analyses of the genus Stefania have indicated that species boundaries and phylogenetic relationships are often incongruent with morphological traits in that clade. A substantial number of "taxonomically cryptic" species, often microendemic, remain to be described. This is notably the case for an isolated population from the summit of Wei-Assipu-tepui, a small table-top mountain at the border between Guyana and Brazil. That population was previously known as Stefania sp. 6 and belongs to the S. riveroi clade. The new species is phylogenetically distinct, but phenotypically extremely similar to S. riveroi, a taxon found only on the summit of Yuruaní-tepui in Venezuela and recovered as sister to all the other known species in the S. riveroi clade. The new taxon is described based on morphology and osteology. Data about genetic divergences within the S. riveroi clade are provided. A new synapomorphy for the genus Stefania is proposed: the presence of a distal process on the third metacarpal. Amended definitions are offered for the three other species in the S. riveroi clade (S. ayangannae, S. coxi, S. riveroi). The new species should be listed as Critically Endangered according to IUCN criteria. [ABSTRACT FROM AUTHOR]

Many anuran species remain to be formally named and described in Amazonia, notably in the Guiana Shield, and particularly in megadiverse groups such as Pristimantis. Several species in the Guiana Shield region have been confused with Pristimantis marmoratus and P. ockendeni. Hylodes grandoculis, a taxon previously placed in the synonymy of P. marmoratus, may be available for one of these species. To disentangle this confusing situation, we examined the external morphology and osteology (via µ-CT scans) of the holotype of H. grandoculis, the holotype of Pristimantis marmoratus, and of recently collected material for which we also analyzed molecular, acoustic, and morphological variation. We concluded that some populations from Suriname and northern Pará, Brazil, are distinct from P. marmoratus and correspond to Pristimantis grandoculis. Other populations, from French Guiana, are closely related to P. grandoculis but their status remains ambiguous. Finally, some populations, from French Guiana and Amapá, Brazil, are conspicuously distinct from both P. marmoratus and P. grandoculis and are described herein as P. crepitaculus sp. nov. A third species, belonging to a "trans-amazon complex", occurs in southern Suriname, Guyana, and Brazil and remains undescribed. Pristimantis grandoculis and related populations from French Guiana lack external tympanum, columella, pharyngeal ostia, vocal slits and do not vocalize. This represents a rare, perhaps unique, example of a deaf and mute species of frogs from the Amazonian lowlands. [ABSTRACT FROM AUTHOR]

To date, there has been no published investigation on the trophic diversity in any tepui summit vertebrate. In this paper, we analyzed the dietary composition of a tepui summit endemic toad, Oreophrynella quelchii from Roraima‐tepui, and compared it with that of O. nigra from Kukenán‐tepui, to examine to what extent diet differs between these two sister species across isolated, although neighboring, tepui tops. The digestive tracts of a total of 197 toads were dissected: 111 from O. quelchii and 86 from O. nigra. The diet composition of O. quelchii was relatively diverse, with 13 major prey categories; mites (Acari, 36.5%) and beetles (Coleoptera, 21.0%) numerically dominated its diet. Despite occurring on two different tepui summits, O. quelchii and O. nigra exhibited a similar diet composition, although in O. nigra mites (Acari, 42.4%) and hymenopterans (especially ants, 16.9%) numerically dominated the diet. The present data suggest that tepui summit Oreophrynella species are flexible in their diet and are active foragers that also feed on aquatic arthropods, successful strategies in tepui competitive environments. [ABSTRACT FROM AUTHOR]

The aromobatid frog Allobates amissibilis sp. nov. is described from a very limited area in the Iwokrama Mountains at elevations between 160 and 950 m, in central Guyana, South America. The new taxon is diagnosed from other Allobates species by morphology, bioacoustics, and genetics, and can be distinguished readily from known congeners by cryptic colouration, small size (16.3–17.8 mm snout-vent length), absence of distinct dorsal pattern in living adult individuals, presence of a distinctly enlarged tubercle on each eyelid, diffuse broad oblique lateral stripe extending from groin to about midbody length, sexually dimorphic throat colouration (pinkish grey, suffused with dark pigment in male, immaculate cream to yellow in female), belly cream to yellow in both sexes, and distinct vocalisation formed by calls of usually 9–12 notes emitted between silent intervals of usually ca . 2–6 s, with a dominant frequency ranging from 5,064 to 5,845 Hz. The new species is the third microendemic reported from the Iwokrama Mountains together with the caecilian Caecilita iwokramae and the lizard Gonatodes timidus. We recommend considering the conservation status of the new species as Data Deficient, and highlight that environmental impact assessments are needed to refine its IUCN threat status. [ABSTRACT FROM AUTHOR]

The article focuses on a research work conducted to assure the presence of the sphaerodactylid lizard, gonatodes vittatus in Guyana. It mentions that the rediscovery of gonatodes vittatus have been made according to the specimens collected in the urban area of Georgetown, Guyana. It also mentions that this lizard primarily inhabits seashores, thorn scrubland and forest edges. It reports on the specimens deposited in the herpetological collections of the Royal Belgian Institute of Natural Sciences, Brussels, Belgium. It also reports that several authors have assured the occurrence of this species in Guyana on the basis of various voucher specimens.

Anomaloglossus is a species-rich genus of frogs endemic to the Guiana Shield that still harbors several unnamed species. Within the A. stepheni species group (which includes four valid nominal species), A. baeobatrachus has an uncertain taxonomic status, notably because the holotype was an unvouchered specimen depicted in a popular journal. Another member of this group, A. leopardus, was only superficially described, lacking information on the sex of specimens in the type series and on advertisement call. Therefore, these two taxa need clarifications in order to allow the description of the extant undescribed species. In this paper, we redescribe A. baeobatrachus based on newly collected material from the species type locality and provide information about its reproductive ecology. We also provide an amended definition of A. leopardus using newly collected material from its type locality. These two species form a clade along with a third species from the Eastern Guiana Shield, which is also described herein. The reproductive biology of A. baeobatrachus and A. stepheni is very similar. Both species have endotrophic and nidicolous tadpoles, despite being distantly related, suggesting independent evolution of this breeding mode. The new species and A. leopardus, on the other hand, have exotrophic tadpoles.

We describe a new Pristimantis from French Guiana, northern South America, which is mainly distinguished from known phenotypically related congeners (i.e. species from the polyphyletic unistrigatus species group) occurring at low and middle elevations in the Guiana Shield by the combination of a distinct tympanum, a lower ratio of tibia vs. hand length, a reddish groin region, and a distinct advertisement call consisting of clusters of generally four short notes. The new species inhabits pristine primary forests on the slopes of isolated massifs reaching more than 400 m elevation, and seems not to occur below ca. 200 m above sea level. Such a sharp altitudinal limit suggests a strong influence of thermal variation on the distribution of the species, and therefore a potential sensitivity to climate change. With only nine isolated populations documented so far, the new species should be prioritized for conservation. Historical climate fluctuations during the Quaternary are likely responsible for the distribution pattern of the new species.