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Range fragmentation poses challenges for species persistence over time and can be caused by both historical and contemporary processes. We combined genomic data, phylogeographical model testing and palaeoclimatic niche modelling to infer the evolutionary history of the Pine Barrens tree frog (Hyla andersonii), a seepage bog specialist, in eastern North America to gain a better understanding of the historical context of its fragmented distribution. We sampled H. andersonii populations across the three disjunct regions of the species range: Alabama/Florida (AF), the Carolinas (CL) and New Jersey (NJ). Phylogenetic relationships within H. andersonii were consistent between the nuclear species tree and mitochondrial analyses, indicating divergence between AF and CL/NJ (Atlantic clade) ~0.9 Mya and divergence of the NJ clade ~0.15 Mya. Several predictions of north-eastern expansion along the Atlantic coast were supported by phylogeographical analyses. Model testing using genome-wide single nucleotide polymorphism data and species distribution models both provided evidence for multiple disjunct refugia. This comprehensive phylogeographical study of H. andersonii demonstrates a long history of range fragmentation within an endemic coastal plain species and highlights the influence of historical climate change on the current distribution of species and their genetic diversity.

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 bufonids in having opposable digits. Osteological synapomorphies confirmed for the genus are as follows: presence of parietal fontanelles and exposed frontoparietal fontanelle, absence of quadratojugal, five presacral vertebrae, distally enlarged terminal phalanges and urostyle greatly expanded into flanges. Ancestral character reconstruction indicates that arboreal habits in some Oreophrynella species are likely to have evolved after the evolution of opposable digits. Opposable digits, in combination with an extension of the interdigital integument and the relative length/orientation of the digits, are likely to be adaptations to facilitate life on rocky tepui summits and an exaptation to arboreality. Cranial simplification in Oreophrynella, in the form of cranial fontanelles and absence of the quadratojugal, is possibly driven by a reduction of developmental costs, increase in flexibility and reduction of body weight. Cranial simplification combined with the shortening of the vertebral column and the shift towards a partly firmisternal girdle might be adaptations to the peculiar tumbling behaviour displayed by Oreophrynella.

Made available in DSpace on 2019-10-04T12:36:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Guyana Environmental Protection Agency Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fonds voor Wetenschappelijk Onderzoek Vlaanderen Belgian Directorate-General for Development Cooperation King Leopold III Fund for Nature Exploration and Conservation National Science Foundation National Geographic 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 this hylid tribe. Our results reveal Myersiohyla to be paraphyletic with respect to B. liliae. Support for the placement of Myersiohyla kanaima is poor, but this taxon is recovered as the sister taxon of the other Cophomantini genera (excluding Myersiohyla) or as the sister taxon of the remaining species of Myersiohyla (including B. liliae). These results lead us to propose two taxonomic changes in order to remedy the paraphyly of Myersiohyla: (1) a new genus is described for M. kanaima, and (2) Boana liliae is transferred to Myersiohyla. We further provide notes on the natural history and vocalizations of the new monotypic genus, a new diagnosis of the former B. liliae in the context of Myersiohyla, and discuss the evolution of tadpole morphology and biogeography of the earlier diverging clades of Cophomantini. Univ Estadual Paulista, Dept Zool, Lab Herpetol, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Vrije Univ Brussel, Biol Dept, Amphibian Evolut Lab, Pleinlaan 2, B-1050 Brussels, Belgium Univ Mississippi, Box 1848, University, MS 38677 USA Coastal Plains Inst & Land Conservancy, 1313 Milton St, Tallahassee, FL 32303 USA Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Div Herpetol, Angel Gallardo 470,C1405DJR, Buenos Aires, DF, Argentina Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Biodiversidad & Biol Expt, Buenos Aires, DF, Argentina Univ Estadual Paulista, Dept Zool, Lab Herpetol, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil CNPq: 158681/2013-4 Guyana Environmental Protection Agency: 100703BR009 Guyana Environmental Protection Agency: 011206BR065 Guyana Environmental Protection Agency: 120707BR075 Guyana Environmental Protection Agency: 061212BR020 Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT): PICT 2013-404, 2015-820 FAPESP: 2012/10000-5 FAPESP: 2013/50741-7 Fonds voor Wetenschappelijk Onderzoek Vlaanderen: FWO12A7614N/FWO12A7617N National Science Foundation: DEB-0206562 National Geographic: 7509-03

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 material from Kaieteur National Park and from the slopes of Maringma-tepui in Guyana. We also describe the previously unknown vocalization and breeding ecology of the species, and conducted an exploratory molecular analysis of the phylogenetic relationships within the genus Pristimantis represented by the members of the “unistrigatus species group” in the Guiana Shield. Pristimantis marmoratus is a small-sized species mainly distinguished from its known Guiana Shield congeners by the combination of F I < II, SVL ≤ 20.4 in males, presence of vocal slits in males, granular/pustulate dorsal skin with well-developed scapular ridges, basal webbing between fingers, fringes on fingers and toes, crossed iris, diffuse yellow or pale green wash on groin, and absence of flashy colour on axillary/pre-axillary region. The advertisement call consists of a single note repeated at a rate of ca 11 calls/min with a dominant frequency ranging from 2756 to 3101 Hz. Pristimantis marmoratus is primarily arboreal, exclusively active at dusk, and probably restricted to the pristine rainforests of the Pantepui uplands and highlands, east of the Gran Sabana between ca 600 and 1800 m above sea level. Preliminary molecular analyses recovered Pristimantis marmoratus as sister to an unnamed species from the Eastern Guiana Shield. On grounds of the newly established distributional extent we suggest maintaining the IUCN conservation status as Least Concern.

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 Pantepui endemic amphibian, which was recently shown to have vicariantly diverged from Pantepui highlands widespread Oligocene ancestors. Location The fractured island-like topography of the Pantepui biogeographical region in north-eastern South America. Methods We inferred the molecular phylogeny of Oreophrynella and other “basal” Bufonidae genera using three mitochondrial and two nuclear DNA sequences under Bayesian and maximum likelihood methods. We estimated divergence times using a relaxed-clock model and reconstructed ancestral areas through multiple models in a common likelihood framework. Results Phylogenetic analyses recovered a monophyletic Oreophrynella sister to Atelopus. Biogeographical analyses strongly suggested colonization of Pantepui via a pre-Miocene (Eocene/Oligocene) long-distance dispersal of a proto-Andean ancestor, followed by pre-Quaternary (lower Miocene) vicariant divergences of main lineages, and endemism of these main lineages to distinct biogeographical subunits. Main conclusions Our results suggest that at least part of the Pantepui diversity stemmed from dispersals from the proto-Andes. Three hypotheses emerge for the origin and evolution of Pantepui endemism, the Distance Dispersal theory, the Plateau theory and the Disturbance–Vicariance theory. Our results indicate that the early diversification of Oreophrynella conforms to that of Stefania, but hint at different factors responsible for the survival or extinction of different tepui summit amphibians.

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 (concatenation and species tree) and morphological (morphometrics, external and hemipenial morphology) analyses confirm Neusticurus rudis as a species complex with several candidate species in the eastern Pantepui region. Neusticurus rudis is here redescribed based on the re-examination of the holotype and 10 specimens from the vicinity of the type locality (ca. 15 km airline) in Guyana. The geographic distribution of N. rudis sensu stricto is restricted to east of the Venezuelan Gran Sabana, extending from the slopes of Mount Roraima in Venezuela through the slopes of Maringma-tepui and Wayalayeng to Mount Ayanganna in Guyana, between 678 and 1500 m elevation. Populations tentatively assigned to N. rudis also occur from Mount Wokomung in the Pakaraima Mountains of Guyana to the Iwokrama Forest Reserve in Guyana, between 159 and 1234 m elevation. A new Neusticurus species is described from the uplands and highlands of the eastern Pantepui region, west of the Venezuelan Gran Sabana in Brazil and Venezuela, between 900 and 2200 m elevation. Populations provisionally assigned to the new species were also found from the La Escalera region to Chivatón, the summit of Abakapá-tepui and the slopes and summit of Auyán-tepui, Venezuela, between 1100 and 2203 m elevation. Our results suggest the Gran Sabana as a possible recent biogeographical barrier for the genus in the region and indicate that tepui-summit Neusticurus populations derive from uplands populations that shifted their habitat preference. www.zoobank.org/lsid:zoobank.org:pub:33DCF862-11CF-4FD0-B4D6-706E2C6A339E.

The Coastal Plain of the southeastern U. S. is one of the planet’s top biodiversity hotspots and yet many taxa have not been adequately studied. The plethodontid salamander, Desmognathus auriculatus, was originally thought to occur from east Texas to Virginia, a range spanning dozens of interfluves and large river systems. Beamer and Lamb (2008) found five independent mitochondrial lineages of what has been called D. auriculatus in the Atlantic Coastal Plain, but did not examine the extensive distribution of D. auriculatus in the Gulf Coastal Plain. We present morphological and molecular genetic data distinguishing two evolutionarily independent and distantly related lineages that are currently subsumed under the taxon D. auriculatus in the eastern Gulf Coastal Plain. We describe one of these as a new species, Desmognathus valentinei sp. nov., and assign the second one to D. auriculatus which we formally redescribe.

Aim: To investigate the influence of tepuian geomorphology on species diversi- fication in the Pantepui biogeographical region based on the phylogenetic rela- tionships 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 South America, one of the least accessible and least studied areas in the world. Methods: Two mitochondrial and two nuclear DNA sequences from 60 indi- viduals of Stefania from 24 localities in Pantepui were employed to infer phylo- genetic affinities and estimate divergence times within the genus using both concatenation and species tree analyses. Ancestral areas were inferred using multiple models in a common likelihood framework. Results: Phylogenetic analyses revealed high diversity in the genus Stefania with 10 candidate species in the Eastern Pantepui District. Four strongly supported clades are recovered in the area, one being exclusively composed of microen- demics on isolated tepui summits. Biogeographical analyses suggest episodes of fragmentation of widespread tepuian ancestors from the onset of diversification of the genus, estimated in the Oligocene (c. 26 Ma), therefore suggesting a neglected vicariant model of Pantepui evolution, the Plateau Theory. Main conclusions: Although our results suggest that vicariance played an important role in the diversification of Stefania, speciation in Pantepui fol- lowed an intricate pattern implying multiple nonexclusive processes. Vicariance and dispersal likely influenced diversification patterns of the Pantepui fauna, possibly according to the following sequence: (1) Cenozoic vicariance; (2) reor- ganization of species diversity due to periods of climatic instability; (3) recent invasions (Pleistocene) of widespread upland taxa.

Biodiversity hotspots are conservation priorities. We identify the North American Coastal Plain (NACP) as a global hotspot based on the classic definition, a region with > 1500 endemic plant species and > 70% habitat loss. This region has been bypassed in prior designations due to misconceptions and myths about its ecology and history. These fallacies include: (1) young age of the NACP, climatic instability over time and submergence during high sea-level stands; (2) climatic and environmental homogeneity; (3) closed forest as the climax vegetation; and (4) fire regimes that are mostly anthropogenic. We show that the NACP is older and more climatically stable than usually assumed, spatially heterogeneous and extremely rich in species and endemics for its range of latitude, especially within pine savannas and other mostly herbaceous and fire-dependent communities. We suspect systematic biases and misconceptions, in addition to missing information, obscure the existence of similarly biologically significant regions world-wide. Potential solutions to this problem include (1) increased field biological surveys and taxonomic determinations, especially within grassy biomes and regions with low soil fertility, which tend to have much overlooked biodiversity; (2) more research on the climatic refugium role of hotspots, given that regions of high endemism often coincide with regions with low velocity of climate change; (3) in low-lying coastal regions, consideration of the heterogeneity in land area generated by historically fluctuating sea levels, which likely enhanced opportunities for evolution of endemic species; and (4) immediate actions to establish new protected areas and implement science-based management to restore evolutionary environmental conditions in newly recognized hotspots.

The frog Anomaloglossus roraima was originally described as Colostethus roraima by E. La Marca in 1998 on the basis of a single immature female collected at 2700 m elevation on the upper slopes of Mount Roraima, a tepui (table mountain) located in southeastern Venezuela. We herein provide a redescription of the species on the basis of new material from Wei-Assipu-tepui and Maringma-tepui in Guyana. The redescription includes the first descriptions of the tadpole and vocalization. Anomaloglossus roraima is a small-sized species mainly distinguished from its known congeners in having Finger I < II; fingers with narrow pre- and postaxial unfolded fringes; toes unwebbed (although rudimentary webbing is sometimes present between Toe III and IV) with narrow pre- and postaxial unfolded fringes; symmetrical cloacal tubercles present; dorsolateral stripe usually present, often inconspicuous; ventrolateral stripe absent; oblique lateral stripe absent; no obvious sexual dichromatism in throat, chest and ve...

This work was prompted by the rediscovery in the Natural History Museum, Vienna, of the holotype of Eudaniella(Kunziana) irengis Pretzmann, 1971, the type species of the subgenus Eudaniella (Kunziana) Pretzmann, 1971 (familyPseudothelphusidae). Unique characters of the first male gonopod of this species warrant the recognition of KunzianaPretzmann, 1971, as a valid genus. Kunziana irengis is redescribed here from the holotype and from new materialcollected near the type locality in Guyana, South America, and its affinities with other genera of Kingsleyini are discussed.

Three frogs of a new species found in cloud forests on two nearby mountains in Guyana were included in a molecular phylogeny of 17 nuclear and mitochondrial genes (10,739 aligned sites) that revealed that their closest relative is Terrarana (Brachycephalidae, Craugastoridae, Eleutherodactylidae, and Strabomantidae) and their next-closest relative is Hemiphractidae (marsupial frogs). We place these frogs in a new family, genus, and species which is strongly supported as the basal clade within Terrarana: Ceuthomantidae n. fam., Ceuthomantis smaragdinus n. gen, n. sp. Morphological evidence supports the placement of two other species from the Guiana Highlands, Pristimantis aracamuni (BarrioAmorós & Molina) and P. cavernibardus (Myers & Donnelly), in the new family and genus. This close phylogenetic relationship of terraranans and marsupial frogs, nearly all of which have direct development, supports an hypothesis that direct development evolved early in the evolution of this huge clade (~1000 species), for which we propose the unranked taxonomic epithet Orthobatrachia.

Three new species of rainfrogs of the genus Pristimantis are described from a large mesa (tepui), the Wokomung Massif, of the Pakaraima Mountains in west-central Guyana. Pristimantis dendrobatoides n. sp. is known from 1385–1411 m, P. jester n. sp. from 1411–1650 m, and P. saltissimus n. sp. from 698–1560 m elevation. The three species are syntopic at elevations around 1400 m in cloud forest. All three taxa are unusual among species of Pristimantis in the production of malodorous and distasteful skin secretions when handled, conditions that are atypical for the genus. Two of the new species (P. dendrobatoides, P. jester) also have bright, red skin coloration, and the third (P. saltissimus) is either cryptically colored or brightly colored.

Gully-eroded and steephead valleys on Eglin Air Force Base in the Florida panhandle were sampled for the abundance of four species of ravine-inhabiting, plethodontid salamanders in two separate periods, 25 years apart. In this interval, Desmognathus auriculatus (Southern Dusky Salamander) appears to have gone extinct and the abundance of D. cf. conanti (Spotted Dusky Salamanders) has decreased by about 68%. There was no change in the average abundance of Eurycea cirrigera (Two- lined Salamander). Pseudotriton ruber (Red Salamanders) declined in ravines from which larger populations of D. auriculatus disappeared, but increased in ravines from which smaller populations of D. auriculatus had disappeared. There was a slight increase in the average abundance of P. ruber in ravines that were inhabited by D. cf. conanti, but those changes in P. ruber abundance were unrelated to the changes in the abundance of D. cf. conanti. Declines in populations of D. auriculatus were also noted in Louisiana and Georgia; evidence suggests that all of these declines began in the mid- 1970s. There are several potential causes of the regional declines, but no single explanation appears sufficient to explain declines in all populations. Feral pig rooting eliminates the larval seepage habitat of desmognathine salamanders and may be partly responsible for the declines on Eglin Air Force Base.

The known diversity of dart-poison frog species has grown from 70 in the 1960s to 247 at present, with no sign that the discovery of new species will wane in the foreseeable future. Although this growth in knowledge of the diversity of this group has been accompanied by detailed investigations of many aspects of the biology of dendrobatids, their phylogenetic relationships remain poorly understood. This study was designed to test hypotheses of dendrobatid diversification by combining new and prior genotypic and phenotypic evidence in a total evidence analysis. DNA sequences were sampled for five mitochondrial and six nuclear loci (approximately 6,100 base pairs [bp]; x¯ = 3,740 bp per terminal; total dataset composed of approximately 1.55 million bp), and 174 phenotypic characters were scored from adult and larval morphology, alkaloid profiles, and behavior. These data were combined with relevant published DNA sequences. Ingroup sampling targeted several previously unsampled species, including Ar...

3%ofthisonce-widespreadecosystem remains (Ware et al. 1993). Longleaf pine sa-vannas are home to at least 35 amphibian, 46 reptile, 45bird, and 36 mammal species, many of which depend al-mostexclusivelyonlongleafpinesavannas(Means2004).Manyresearchershaveconcludedthattheseandotheran-imals benefit from maintenance of longleaf pine savannaby prescribed burning (Mushinsky 1985; Engstrom 1993;James et al. 1997). Because natural fires no longer sweepthrough remaining tracts of longleaf pine, land managersmust apply prescribed burns to simulate the rejuvenat-ing effects of fire (Brennan et al. 1998). In the past twodecades, the frequency of prescribed burns has been rec-ommended on ever shorter intervals to restore habitatfeatures eroded by decades of fire suppression (Engstromet al. 1984; Cox et al. 1987; Weigl et al. 1989; Engstrom1993; Tucker & Robinson 2003; Means 2004).Schurbon and Fauth (2003) suggest decreasing the fre-quency of prescribed burns from the current 2–3 years to3–7 years in order to “better maintain diverse amphibianand plant” assemblages in southern pine forests. Theirsuggestion was based on a 1-year study of amphibianssampled at 15 ponds within the Francis Marion NationalForest, South Carolina. We believe that their study designand sampling effort were inadequate and, therefore, thattheir conclusions may be invalid. For reasons elaboratedbelow, we discourage land managers from following theirrecommendationandsuggestthata1-to3-yearfire-returninterval be the goal for prescribed fire in pine forests ofthe southeastern U.S. coastal plain.

The Eurycea quadridigitata complex is currently composed of the nominate species and E. chamberlaini, with no other species recognized. However, recent molecular studies have revealed at least five genetic lineages within this species complex, with one lineage more closely related to the neotenic Eurycea species of central Texas and E. chamberlaini nested within E. quadridigitata sensu lato. We use large-scale geographic sampling in combination with a multilocus species delineation method and morphology to test whether these genetic lineages represent distinct species under the general lineage concept of species. We describe two new species of salamander from this complex, resurrect and elevate a former subspecies to full species status, add to the diagnosis of E. chamberlaini, and redefine E. quadridigitata in the context of this revision. All five species are diagnosable from one another through a number of meristic, morphometric, molecular, and ecological criteria.

Morphology of kingsnakes, Lampropeltis getula, is described and analyzed in the Apalachicola region of the Florida panhandle. Populations inhabiting the eastern Apalachicola Lowlands, a distinct biotic province, are different from the surrounding populations in having fewer and wider light body crossbands, distinct ontogenetic interband lightening, unique ventral patterns, and the presence of non-banded (striped and patternless) individuals. We conclude that the name L. g. goini as well as the hypothesis that Apalachicola L. getula are relict populations of intergrades between L. g. getula and L. g. floridana are invalid. We believe the polymorphic eastern Apalachicola Lowlands populations are most closely related to L. g. getula, and evolved in isolation on a barrier island or the coastal strand of a peninsula during one of the many higher stands of sea in the Pleistocene.

The largest known breeding migration of the flatwoods salamander (Ambystoma cingulatum) was monitored over a 22-year period following its discovery in 1970 in Liberty County, Florida (U.S.A.). Nightly migrations of 200–300 adults across a 4.3-km stretch of paved highway in 1970–1972 had dwindled to less than one individual per night in 1990–1992; the decline apparently was already underway in the 1980s. We discuss possible natural and anthropogenic causes of the decline. The silvicultural practice of converting native longleaf pine savanna to bedded slash pine plantation, implemented on our study site about 1968, may have interfered with migration, successful hatching, larval life, feeding, and finding suitable cover post-metamorphosis. Longleaf pine-wiregrass flatwoods inhabited by adults have been drastically reduced and severely degraded throughout the coastal plain and may explain why the species is rare and deserving of threatened status. La mas grande migracion de crias conocida de la salamandra “flatwoods” (Ambystoma cingulatum) se seguio muy de cerca durante un plazo de 22 anos despues de su descrubrimiento en 1970 en el condado de Liberty, Florida. Las migraciones nocturnas de 200–300 adultos en 1970–1972 a traves de un tramo de 4.3 kilometros de carretera pavimentada habian disminuido a menos de un individuo por noche en 1990–1992. Segun parece, la disminucion ya estaba en marcha en los anos 1980. Deliberamos sobre posibles causas naturales y antropogenicas de esta disminucion. La practica silvicultural de convertir sabana de pinos “longleaf” autoctonos a plantio de pinos “slash” plantados se efectuo sobre nuestro sitio de estudio en 1968. Es posible que esta practica haya afectado la migracion, la salida de cascaron y la etapa larval de la salamandra, asi como su alimentacion y su habilidad de encontrar donde rirse despues de la metamorfosis. Se han reducido en forma drastica y se han visto afectados los bosques de pino “longleaf” y pasto alambre donde viven los adultos. Estas hechos sirven como posible explicacion de porque la especie ya es rara y merece una clasificacion como especie amenazada.

Summary The Pantepui region of South America, located in southern Venezuela, northern Brazil, and western Guyana, is characterized by table mountains (tepuis) made of Proterozoic (> 1.5 billion years old) sandstone — the highest reaching nearly 3 km — that are isolated from their surroundings by up to 1000 m high vertical cliffs (Figure 1A). Tepuis are among the most inaccessible places on earth (Supplemental information), and the majority of their summits have been visited less than the moon. Due to its age and topography [1,2], this region has been assumed to be an ideal nursery of speciation and a potential inland counterpart to oceanic islands [3,4]. High endemism has been reported for the flora (25% in vascular plants) and fauna (68.5% in amphibians and reptiles) of single tepuis [5,6], and an ancient origin has been postulated for some of these organisms. But, it has also been suggested that a few taxa living in habitats extending from lowlands to summits (e.g., savannah) invaded some of the more accessible tepuis only recently [6–8]. Taken at face value, the overall timing and extent of biotic interchange between tepui summits has remained unstudied. Here, we show that recent faunal interchange among currently isolated tepui summits has been extensive, and affected even taxa living in some of the most tepui-specific habitats and on the most inaccessible summits.

The author describes his experience following 2 bites to his hand by the same green palmsnake (Philodryas viridissimus) on the same day, and reviews the literature on bites from rear-fanged species of the genus Philodryas. Though this genus has long been thought to include the most venomous colubrid snakes in the Americas, the author's bites were relatively asymptomatic. Fatalities caused by Philodryas seem to be lacking in the primary literature, but mild to moderate symptoms do result from envenomations by at least 2 species. Medical researchers are urged to obtain accurate species identifications and to carefully report symptoms and fatalities from bites of colubrid snakes.

Because the Coastal Plain is geologically and biologically a very distinct region of the southeastern United States—the southern portion having a nearly subtropical climate—the life cycles, ecology, and evolutionary relationships of its plethodontid salamanders may be significantly different from plethodontids in the Appalachians and Piedmont. Little attention has been paid, however, to Coastal Plain plethodontids. For instance, of the 133 scientific papers and posters presented at the four plethodontid salamander conferences held in Highlands, North Carolina, since 1972, only three (2%) dealt with Coastal Plain plethodontids. And yet, while it possesses fewer total species than the Appalachians and Piedmont, the Coastal Plain boasts of slightly more plethodontid diversity at the generic level. The genera Phaeognathus, Haideotriton, and Stereochilus are Coastal Plain endemics, whereas in the Appalachians and Piedmont Gyrinophilus is the only endemic genus unless one accepts Leurognathus apart from Desmognathus. In addition, Aneides is found in the Appalachians and not the Coastal Plain, but the genus also occurs in the western U.S. All the rest of the plethodontid genera east of the Mississippi River are shared by the Coastal Plain with the Appalachians and Piedmont.

Individuals representing the three recognized extant species of the salamander family Amphiumidae were collected and subjected to protein analysis by horizontal starch-gel electrophoresis. Products of 24 presumptive genetic loci (22 enzymes and hemoglobins) were resolved for all individuals. Estimates of individual heterozygosity (H = 0.0790.096) and percent polymorphic loci (95% criterion, 29.2% for each species) were higher than those reported for other aquatic salamander species. These results are interpreted with respect to the low levels of genetic variability reported for several other aquatic salamander species (Shaffer and Breden, 1989). Genetic distance estimates suggest a high level of similarity between Amphiuma means and A. tridactylum (Hillis' 1984 D* = 0.118; Nei's 1978 D = 0.121) and a much greater dissimilarity between A. pholeter and A. tridactylum (D* = 0.710; D = 0.729) or A. pholeter and A. means (D* = 0.858; D = 0.902).

The chorus frog Pseudacris ornata is a fossorial species that uses its forelimbs to burrow in the substrate. This is highly unusual as the great majority of burrowing frogs dig backwards with their hind feet. Pseudacris ornata is quite similar in manner of forelimb burrowing to its nearest relative Pseudacris streckeri. However, P. ornata shows greater hesitancy to burrow and thus is intermediate between the highly fossorial P. streckeri and another species, Pseudacris triseriata, which is not known to burrow . In morphological adaptations of the forelimb for burrowing, P. ornata is also intermediate between the other two species. Pseudacris ornata spends much of its time underground outside its breeding season, and is associated with easily penetrated sandy soils. Pseudacris ornata occasionally communicates underground by vocalization. This type of communication may be of an aversive nature. Forward burrowing may have evolved in salientians to facilitate subterranean feeding or other behaviors requiring efficient orientation using sensory structures on the anterior half of the body.

A new strabomantid frog of the genus Pristimantis Jiménez de la Espada, 1871 is described from the Eastern Pantepui Region, Guiana Shield, northern South America. The new species, Pristimantis aureoventris sp. nov., is known so far from two neighbouring tepuis, namely Wei Assipu Tepui (type locality) at the border between Guyana and Brazil and Mount Roraima in Guyana, and occurs between 2210–2305 m elevation. The new taxon is distinguished from all known congeners by the following combination of characters: Finger I < II; tympanum distinct; basal webbing between Toes IV-V; broad lateral fringes on fingers and toes; ventral skin areolate; vocal slits absent in male; two non-spinous whitish nuptial pads and vocal sac present in male; high degree of pattern polymorphism; throat, chest, and belly golden yellow, usually with reddish brown to dark brown mottling; internal organs little or not visible through the ventral skin in life. The call of the new species consists of bouts of a single amplitude-modulated (decreasing to the end) note repeated at a rate of ca. 18 notes/min with a dominant frequency ranging from 2180 to 2430 Hz.

We examine the peninsula effect for Florida's amphibians and reptiles. Of 108 species that inhabit the peninsula, forty-eight fail to reach the peninsular tip. These form an unusually large concentration of tipward boundaries in a few counties along the mid-peninsula axis. A Monte Carlo simulation suggests that this concentration would not likely have arisen if the species boundaries were randomly and independently arranged. Nor is it likely that this peninsula effect is a historical legacy or a result of immigration-extinction dynamics. All but one of the forty-eight species sort into four natural groups by habitat preferences. Each of the four habitat categories either disappears or declines in per cent occurrence and/or quality tipward along the peninsula. By contrast, only one of the sixty-one species that inhabit the tip of the peninsula fails to reach the peninsular base. We believe the habitat reduction alone explains the peninsula effect in the Florida herpetofauna.

The geographic distributions of two congeneric salamanders interdigitate in western Florida. A Coastal Plain endemic species (Desmognathus auriculatus) occurs throughout coastal swamps in ana between major drainages; it disperses upstream into drainages from population centres near drainage mouths. Desmognathus fuscus is a northern species (at its southern distributional limits in Florida) that disperses downstream in drainages from headwater population centres. Florida habitats occupied by either species can be ordered along a gradient ranging from lotic waters of first order streams (including the unique 'steepheads') to lentic conditions of swamps, sloughs, and lake margins. When allopatric, D. auriculatus occurs over the entire range of habitats and especially in steepheads; but where sympatric with D. fuscus, D. auriculatus occurs only in stream habitats greater than order 2. In several adjacent