Philippe J. R. Kok

Philippe J. R. Kok
University of Lodz · Department of Ecology and Vertebrate Zoology

PhD in Biology

About

187
Publications
71,038
Reads
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3,280
Citations
Citations since 2016
34 Research Items
2119 Citations
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300
20162017201820192020202120220100200300
Introduction
Additional affiliations
January 1993 - present
Royal Belgian Institute of Natural Sciences
Position
  • Research Associate

Publications

Publications (187)
Article
Aim To investigate the influence of tepuian geomorphology on species diversification in the Pantepui biogeographical region based on the phylogenetic relationships and divergence times of tepui-endemic clades of stefania frogs (Stefania, Hemiphractidae). Location The ‘tepuis’ and uplands/lowlands of the Pantepui biogeographical region of northern...
Article
Aim: Using the Pantepui palaeoendemic toad genus Oreophrynella, we explored (1) the origin of Pantepui endemism and the hypothesis of Pantepui being a source of diversity for the surrounding areas, including the geologically younger Andes; (2) whether early diversification of Oreophrynella conforms with that of Stefania (Hemiphractidae), another Pa...
Article
Tepuis are Precambrian sandstone tabletop mountains in South America that can reach up to ~3,000 m in elevation. Their highest summits are both physiographically and ecologically isolated from the surrounding upland savannah and lush tropical rainforest, and they face particularly hostile, challenging environmental conditions.Taxa thriving on high...
Article
The only study of the osteology of the toad genus Oreophrynella dates back to 1971 and was based on a single species. Here, we use high-resolution X-ray microcomputed tomography to analyse the osteology of all nine described Oreophrynella species, which are compared with representatives of other bufonid lineages. Oreophrynella is unique among bufon...
Article
Full-text available
The remoteness and isolation of South American tabletop mountain (tepui) summits may protect against infections that underpin global amphibian declines. Increases in recreational pressure in such unspoiled destinations, and in isolated ecosystems globally, pose a poorly understood risk of wildlife disease introduction, especially in supposedly immu...
Article
Full-text available
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 Pristi- mantis marmoratus and P. ockendeni. Hylodes grandoculis, a taxon previously placed in the synonymy of P. mar...
Article
Major historical landscape changes have left significant signatures on species diversification. However, how these changes have affected the build-up and maintenance of Amazonia’s megadiversity continues to be debated. Here, we addressed this issue by focusing on the evolutionary history of a pan-Amazonian toad genus that has diversified throughout...
Article
The genus Pipa is a species-poor clade of Neotropical frogs and one of the most bizarre-looking due to many highly derived anatomical traits related to their fully aquatic lifestyle. With their African relatives, they form the Pipidae family, which has attracted much attention, especially regarding its anatomy, reproductive biology, paleontology an...
Article
Full-text available
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 be- tween these two...
Article
The genus Synapturanus includes three nominal species of fossorial Amazonian frogs. A previous study combining molecular, morphological and acoustic data suggested that there may be six times more species than currently recognized. Herein we describe and name three of these new species and compare their osteology. Synapturanus zombie sp. nov. occur...
Article
The outstanding biodiversity of the Guiana Shield has raised many questions about its origins and evolution. Frogs of the genera Adelastes, Otophryne and Synapturanus form an ancient lineage distributed mostly across this region. These genera display strikingly disparate morphologies and life-history traits. Notably, Synapturanus is conspicuously a...
Article
Aim We investigate the spatiotemporal context of the diversification of Allobates, a widespread genus of Amazonian frogs with high species diversity particularly in western Amazonia. We tested if that diversity originated in situ or through repeated dispersals from other Amazonian areas and if this diversification took place during or after the Peb...
Article
Full-text available
Anomaloglossus is a species-rich genus of frogs endemic to the Guiana Shield that still harbours several unnamed species. According to a recent integrative taxonomic survey, the A. stepheni species group includes five valid nominal species and at least four putatively unnamed species, two in Brazil and two in Suriname. In this paper, we describe th...
Article
Aim: Mapping Amazonian biodiversity accurately is a major challenge for integrated conservation strategies and to study its origins. However, species boundaries and their respective distribution are notoriously inaccurate in this region. Here, we generated a georeferenced database of short mtDNA sequences from Amazonian frogs, revised the species r...
Article
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...
Article
The non-monophyly of both the genus Myersiohyla and the Boana punctata group has been recovered in a number of published phylogenetic analyses. In this paper we report on the analysis of sequences of Boana liliae, a species originally assigned to the B. punctata group, in a dataset of Cophomantini that recovered novel phylogenetic relationships for...
Article
The non-monophyly of both the genus Myersiohyla and the Boana punctata group has been recovered in a number of published phylogenetic analyses. In this paper we report on the analysis of sequences of Boana liliae, a species originally assigned to the B. punctata group, in a dataset of Cophomantini that recovered novel phylogenetic relationships for...
Article
Neotropical sipo snakes (Chironius) are large diurnal snakes with a long tail and big eyes that di er from other Neotropical snakes in having 10 or 12 dorsal scale rows at midbody. The 22 currently recognized species occur from Central America south to Uruguay and northeastern Argentina. Based on the largest geographical sampling to date including...
Article
Full-text available
Recent extinctions and drastic population declines have been documented in the Guiana Shield endemic frog genus Anomaloglossus, hence the importance to resolve its alpha-taxonomy. Based on molecular phy-logenies, the literature has long reported the occurrence of an undescribed species in the Pakaraima Mountains of Guyana in the Pantepui region. We...
Article
DOI: 10.1111/zsc.12273; ORIGINAL ARTICLE: Reconquering the water: Evolution and systematics of South and Central American aquatic lizards (Gymnophthalmidae) Sergio Marques-Souza1 | Ivan Prates2 | Antoine Fouquet3 | Agustín Camacho1 | Philippe J. R. Kok4 | Pedro M. S. Nunes5 | Francisco Dal Vechio1 | Renato Sousa Recoder1 | Nathalia Mejia1 | Mauro T...
Article
The Cercosaurini tribe stands out from other Gymnophthalmidae lizards for including several species with morphological adaptations to aquatic lifestyle (“Crocodile- Like Morphology” – CLM). Recent molecular phylogenies of Cercosaurini demonstrated the paraphyly of CLM species, implicitly suggesting that adaptations to the aquatic life evolved more...
Article
Full-text available
The gymnophthalmid lizard genus Neusticurus Duméril and Bibron, 1839 currently contains six described species. One of them, Neusticurus rudis Boulenger, 1900 has a long history of taxonomic confusion, and uncertainty remains about the number of species involved under that name, especially in the Pantepui region. Our molecular phylogenetic (concaten...
Article
Full-text available
A large portion of the amphibian species occurring in Amazonia remains undescribed. A recent study on species delinea-tion in Anomaloglossus, a genus endemic to the Guiana Shield, demonstrated the existence of two undescribed species previously identified as A. degranvillei, which we describe herein. In addition to divergence at the molecular level...
Article
Full-text available
The frog Pristimantis marmoratus was originally described as Hylodes marmoratus by George A. Boulenger in 1900 based on a single specimen reported to have been collected at the foot of Mount Roraima in Guyana in 1898. We herein discuss the exact location of the type locality of P. marmoratus and provide a redescription of the species based on new m...
Article
Full-text available
Hatching synchrony is wide-spread amongst egg-laying species and is thought to enhance offspring survival, notably by diluting predation risks. Turtle and snake eggs were shown to achieve synchronous hatching by altering development rates (where less advanced eggs may accelerate development) or by hatching prematurely (where underdeveloped embryos...
Article
Full-text available
Vocalizations of anuran amphibians have received much attention in studies of behavioral ecology and physiology, but also provide informative characters for identifying and delimiting species. We here review the terminology and variation of frog calls from a perspective of integrative taxonomy, and provide hands-on protocols for recording, analyzin...
Article
Lack of resolution on species boundaries and distribution can hamper inferences in many fields of biology, notably biogeography and conservation biology. This is particularly true in megadiverse and under-surveyed regions such as Amazonia, where species richness remains vastly underestimated. Recently, integrative approaches using a combination of...
Article
Full-text available
Egg-clustering and communal nesting behaviours provide advantages to offspring. Advantages range from anti-predatory benefits, maintenance of moisture and temperature levels within the nest, preventing the eggs from rolling, to enabling hatching synchrony through embryo communication. It was recently suggested that embryo communication may extend b...
Article
Full-text available
It has been suggested that the inability to migrate in response to climate change is a key threat to tepui summit biota. Tepui summit organisms might thus seriously be threatened by global warming, and there is an urgent need to accurately evaluate their taxonomic status and distributions. We investigated phylogenetic relationships among several po...
Article
Full-text available
Communication is central to life at all levels of complexity, from cells to organs, through to organisms and communities. Turtle eggs were recently shown to communicate with each other in order to synchronise their development and generate beneficial hatching synchrony. Yet the mechanism underlying embryo to embryo communication remains unknown. He...
Article
Full-text available
We used molecular and morphological data to investigate the hidden diversity within the Hypsiboas semilineatus species group, and more specifically within H. geographicus, an allegedly widespread species in northern South America. As a result, the identity of H. geographicus was clarified, several candidate species were detected and one of them, fr...
Article
Full-text available
We describe a new hylid species of the genus Tepuihyla from Pantepui, northeastern South America. The new species inhabits the Chimantá Massif, Bolívar state, Venezuela. The new species is likely part of a recent non-adaptive radiation, and was confused for more than a decade with T. edelcae, a morphologically similar species occurring on the summi...
Article
Full-text available
It is a common belief that reptile eggs should not be turned after oviposition once the embryo has attached itself to the inner membrane of the shell as it might kill developing embryos. Here, we used 338 eggs from 32 clutches of the water snake Natrix maura to (1) thoroughly describe natural clutch arrangement, (2) experimentally assess the effect...
Article
Full-text available
The gymnophthalmid lizard Riolama inopinata sp. nov. is described from the summit of Murisipán-tepui, Bolívar State, Venezuela. The new species is characterized by its small size, slender body, short neck, chestnut brown dorsum with two conspicuous orange-brown dorsolateral stripes, 30 or 31 mid-dorsal scales, and 18 or 19 ventral scales in transve...
Article
Full-text available
We describe two new species of Anomaloglossus from Roraima State, Brazil, that are likely endemic to single mountains currently isolated among lowland forest and savanna ecosystems. The first species, Anomaloglossus tepequem sp. nov. was collected in 1986 and 1992 along a single stream at >500 m elevation on a tepui-like mountain named Tepequém, bu...
Article
Full-text available
Males of the advanced salamanders (Salamandroidea) attain internal fertilization without a copulatory organ by depositing a spermatophore on the substrate in the environment, which females subsequently take up with their cloaca. The aquatically reproducing modern Eurasian newts (Salamandridae) have taken this to extremes, because most species do no...
Article
AimTo investigate the biogeographical history of the Pantepui region based on the phylogenetic relationships and divergence dates of a tepui-endemic small mammal: the Roraima mouse, Podoxymys roraimae. This mouse is one of the rarest and most restricted mammals in terms of geographical distribution, and its evolutionary position has never been eval...
Article
Full-text available
Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally dist...
Preprint
Full-text available
Throughout the animal kingdom, internal fertilization - the merging of sperm and egg inside the female body - nearly invariably relies on the use of a copulatory organ. In contrast, males of advanced salamanders (Salamandroidea) attain internal fertilization by depositing a spermatophore on the substrate in the environment, which females subsequent...
Preprint
Throughout the animal kingdom, internal fertilization - the merging of sperm and egg inside the female body - nearly invariably relies on the use of a copulatory organ. In contrast, males of advanced salamanders (Salamandroidea) attain internal fertilization by depositing a spermatophore on the substrate in the environment, which females subsequent...
Article
Full-text available
According to current understanding, five lineages of amphibians, but no other tetrapods, are secondarily lungless and are believed to rely exclusively on cutaneous gas exchange. One explanation of the evolutionary loss of lungs interprets lunglessness as an adaptation to reduce buoyancy in fast-flowing aquatic environments, reasoning that excessive...
Technical Report
Listed as Endangered because it is only known from two locations, and it has an area of occupancy (AOO) of 1.41 km2, with an extent of occurrence (EOO) of 4.84 km2. Moreover there is an inferred decline in its area of extent and quality of habitat due to the effects of global warming upon the tepui ecosystem, with expected temperature increases in...
Article
Full-text available
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 mid- dle elevations in the Guiana Shield by the combination of a distinct tympanum, a lower ratio of tibia vs. hand...
Article
Full-text available
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...
Article
Full-text available
We review the taxonomic status of the snakes belonging to the genus Atractus from the Pantepui region on the basis of morphological characters (meristic, morphometric, color pattern, and hemipenis). We redescribe and illustrate the holotype of A. insipidus, correcting the elevation of the type locality and providing its exact coordinates. We report...
Article
Full-text available
Two new colourful species of direct-­developing frogs of the genus Pristimantis are described from the summit of two isolated tepuis (sandstone table mountains) in the Eastern Pantepui District of the Guiana Shield highlands. Pristimantis jamescameroni sp. nov. is described from the summit of Aprada-­tepui from 2557-­2571 m elevation, and P. imthur...
Article
Full-text available
The skin secretion of many amphibians contains an arsenal of bioactive molecules, including hormone-like peptides (HLPs) acting as defense toxins against predators, and antimicrobial peptides (AMPs) providing protection against infectious microorganisms. Several amphibian taxa seem to have independently acquired the genes to produce skin-secreted p...
Data
FASTA file containing the mRNA sequences of the 13 transcriptionally active Silurana tropicalis AMP genes. Coding regions are written in blue; untranslated regions are written in red. (DOC)
Data
Results of an MS/MS ion search against a database of Silurana tropicalis AMP/HLP precursor proteins predicted from cDNA and gene sequences, using an in-house version of MASCOT Server (Matrix Science, USA). Individual ions scores >26 indicate identity or extensive homology (p<0.05). For each of the confirmed peptides, the MS/MS fragmentation spectru...
Article
Full-text available
The type series of Pristimantis guaiquinimensis (Schlüter & Rödder, 2007), P. tepuiensis (Schlüter & Rödder, 2007) and P. stegolepis (Schlüter & Rödder, 2007) have been thoroughly examined. We highlight a number of discrepancies in the original descriptions that do not support the recognition of P. stegolepis and P. tepuiensis as valid species. We...
Article
Full-text available
Spiny-backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight cou...