Both environmental factors and social factors affect an animal's choice of microhabitat. We explored the effects of humidity and the presence of conspecifics and predators on microhabitat selection by Brown-Speckled Sphaeros (Sphaerodactylus notatus; Squamata: Sphaerodactylidae). To test the effect of environmental moisture, we provided geckos a choice between shelters of varying humidity and determined that individuals were significantly more likely to choose more humid shelters. In interaction trials between conspecifics of different sizes and sexes and between geckos and predators, we found that lizards were unwilling to share shelters with conspecifics in all situations. We observed aggressive behaviors such as chasing, biting, and head bobbing and noted that subordinate geckos were unwilling to enter a shelter occupied by a dominant individual even in the presence of a predator.

Anurans have been shown to reduce their activity in the presence of predation-related chemical cues. We exposed tadpoles of the federally endangered Houston Toad, Bufo (Anaxyrus) houstonensis, to three chemical cues: A no-predation cue produced by the presence of only predatory anisopteran nymphs (Anax junius), a conspecific-predation cue produced from the consumption of conspecific tadpoles by A. junius nymphs, and a heterospecific-predation cue produced from the consumption of coastal plain toad (Bufo (Incilius) nebulifer) tadpoles by A. junius nymphs. We measured tadpole activity levels before and after exposure to the cues. Tadpole activity was not influenced by the no-predation cue, but it decreased significantly during exposure to either predation cue. The reduction in activity did not differ significantly between predation cue treatments. These data suggest that: 1) B. houstonensis tadpoles will respond to predation, but not the presence of a predator alone. 2) There may be a chemical homology between the predation cues. 3) When developing with B. nebulifer tadpoles, B. houstonensis may experience negative long-term life historical effects.

Anuros han demostrado reducir su actividad en presencia de señales químicas relacionadas con la depredación. Expusimos los renacuajos del sapo de Houston por el gobierno federal en peligro de extinción, Bufo (Anaxyrus) houstonensis, a tres señales químicas: una señal no-depredación producida por la presencia de depredadores anisopteran ninfas (Anax junius), un taco de galápago-depredación producida a partir del consumo de los renacuajos conespecíficos en junius a ninfas y un taco heteroespecíficas-depredación produjeron de la consumición de los renacuajos de sapo llano costero (Bufo (Incilius) nebulifer) por A. junius ninfas. Antes y después de la exposición de referencia para medir sus niveles de actividad. Actividad de renacuajo no fue influenciada por la señal no-depredación, pero disminuyó significativamente durante la exposición a cualquier señal de depredación. La reducción en la actividad no difirieron significativamente entre los tratamientos con cue depredación. Estos datos sugieren el siguiente. 1) B. houstonensis renacuajos responderá a la depredación, pero no la presencia de un depredador solo. 2) Puede haber una química homología entre las señales de la depredación. (3) Cuando se desarrolla con B. nebulifer renacuajos, B. houstonensis puede experimentar efectos históricos de la vida de largo plazo negativas.

We investigated how tadpoles of Bokermannohyla martinsi (Martin's Treefrog) and Bokermannohyla nanuzae (Jaboticatubas Treefrog) respond to a simulated predator attack. We tested whether escape variables (depths of microhabitats used, promptness to react, and distance covered while fleeing) varied throughout the year, depended on tadpole size, or both. We expected these variables to be relatively constant throughout the year and that smaller individuals would react more promptly to the stimulus, as they are likely more vulnerable to a broader set of predators. We compared depths used by tadpoles before and after fleeing and expected them to move to deeper microhabitats if depth confers extra protection. We also expected tadpoles positioned at deeper microhabitats to take longer to react and to move less. When comparing the two species, we expected the tadpoles of B. nanuzae, which are potentially cryptic to predators, to take longer to react and to flee shorter distances. We also recorded and compared types of stream substrates used before and after escape by each species and compared the two species regarding microhabitat (bottom type and depth) use. Microhabitat preferences differed between species, but microhabitat types were used in the same proportion before and after fleeing by both species. They showed similarity in promptness to react and distance covered while fleeing from a threat, suggesting that their different coloration does not lead to differentiation in these variables.

We quantified the abundance of pelagic sea snakes, Hydrophis (= Pelamis) platurus, while following slicks that formed drift lines during 3 yr of research in the Golfo de Papagayo, Costa Rica. The number of snakes we observed floating on slicks varied greatly and ranged from 0 to 1,029 per hour. The largest number we observed was highly unusual in recent experience but comparable to earlier reports of sea snake aggregations in the historical literature. Snakes were more abundant on slicks with flotsam during early morning hours on clear, calm days. However, ‘decisions' of sea snakes to spend time floating on slicks are also influenced by other factors that are not known or are poorly understood. Neither temperature nor salinity influenced the number of snakes we observed within the range of the parameters we encountered. We observed only a single snake during 13 days of searching during which there were red tide conditions with cold and turbid water disturbed almost daily by high winds. We also counted floating snakes at the inner basin of the Golfo Dulce in southern Costa Rica, where the population of H. platurus contains almost exclusively xanthic (all-yellow) individuals. These snakes are behaviorally different and are most-commonly observed while floating at night, without any strong association with slicks. Mean counts of these xanthic snakes suggest the abundance of pelagic sea snakes is essentially similar in Golfo Dulce (21.4 ± 4.4 snakes/h) and Golfo de Papagayo (19.3 ± 4.4 snakes/h, neglecting the single, unusually high count of 1,029 snakes/h).

Gloydius shedaoensis is an insular endemic and vulnerable pit viper that is restricted to Snake Island, a very small islet in the Bohai Sea of northeastern China. In this study, we used the mitochondrial ND4 gene and eight microsatellite loci to evaluate the genetic structure and amount of genetic diversity in the species. In total, 63 individuals were sampled along eight line transects throughout the range of Snake Island. We found that this vulnerable species presented a remarkably low genetic diversity and moderate inbreeding. No evident genetic or phylogenetic structures were detected within the species, and only two neighboring subpopulations, S-pop1 and S-pop2, showed slight differentiations from others, suggesting the species can be considered as a single unit for future conservation effort. A high level of gene flow was found among subpopulations, and the analyses of relationships between values of individual relatedness and their spatial distributions further showed that closely related individuals tended to scatter throughout the entire island, suggesting widespread dispersals of the insular pit vipers.

Along with the Orinoco and Cuban Crocodiles (Crocodylus intermedius and Crocodylus rhombifer), the American Crocodile (Crocodylus acutus) is among the most threatened crocodylian species in the Americas. Although this species is distributed widely, its IUCN “threat category” in several countries is “of concern.” We review the literature dealing with the biology and conservation status of C. acutus in Colombia and assess its Extent of Occurrence (EoO) and its EoO-Habitat Status. We propose a way to estimate the effective area of optimal habitable occurrence on the basis of the EoO (EoO-Effective Habitable Area). We found that only 37% of the national territories have been sampled in ecological studies during the last decade. The relatively few reports of abundance values and the lack of long-term projects that can produce accurate estimates of population sizes make it difficult to establish the conservation status of this species in Colombia. Our analyses indicate that the EoO-Habitat Status has a higher proportion of disturbed landscapes, as well as agricultural areas, than natural forests and protected areas. We considered that EoO-Effective Habitable Area is a good parameter to estimate the amount of suitable habitat and status of optimal habitat because it does not overestimate the actual areas that crocodiles inhabit. Spatial information gaps, combined with the absence of knowledge about the population ecology and habitat reduction are indeed the principal threats to the American Crocodile in Colombia.

Northern range limits for snakes may result from thermal constraints, especially for oviposition and hibernation. We characterized hibernation and oviposition sites for federally threatened Great Basin Gophersnakes (Pituophis catenifer deserticola) near the edge of their northern-range limit in south central British Columbia, Canada. During 2006 and 2007, most Gophersnakes (75.8%) hibernated alone. At our more northern study area, typical hibernation sites were in grassy hillsides, whereas at our southern study areas snakes hibernated in rocky outcrops. All snakes that denned in rock outcrops reused sites over years, but only 28.6% of snakes that hibernated in rodent burrows reused sites. Most female Gophersnakes (94%) laid eggs in sites that were not used by other females, and reuse of sites was rare (12.5%). Almost all of the oviposition sites were in grassy slopes, with any shrubs and trees more than 5 m away; females selected grassy or sage-steppe cover for oviposition. This pattern of mostly individual and single-use hibernation and oviposition sites suggests that hibernation and oviposition sites are readily available as components of the active-season range within the sage-steppe ecozone, although this habitat is rare and severely threatened within Canada. In terms of species conservation, areas of suitable habitat should be protected based on active-season use, rather than by attempting to find hibernation sites supporting large aggregations of snakes. This recommendation is unlike that for Rattlesnakes (Crotalus spp.) and Gartersnakes (Thamnophis spp.), which often congregate at hibernation sites.

Conservation measures to increase or maintain habitat networks in pond-dwelling amphibians often consist of new breeding ponds to supplement existing ones. We examined the effectiveness of this conservation measure in the European Treefrog (Hyla arborea) by evaluating the speed of colonization and the origin of colonizers using field surveys and genetic methods in an intensively managed agricultural area in Switzerland. One to three years after pond construction, 85 European Treefrogs were found at new ponds, and of these, 30 were identified as migrants by genetic assignment tests. We observed a negative correlation between the number of migrants and geographical distance (r = −0.33): 66% of colonizers originated from ponds nearby (up to 500 m); 30% stemmed from source ponds located at distances between 500 and 2,500 m; and 4% originated from distant ponds (2,500 to 5,400 m). Four colonizers crossed a 25-m wide river. These results show that Treefrogs rapidly colonize new ponds and that the gene pools at these new ponds contain a wide range of genetic variants of a Treefrog population that is patchily structured. Thus, maintaining high pond density is an efficient conservation measure to increase functional connectivity for Treefrogs even in an intensely managed agricultural landscape.

Species' tolerance of and response to fire varies. Environments that experience frequent fires will contain fire-tolerant fauna, whereas fauna that occur in environments that burn infrequently may lack strategies to cope with fire. In 2003, intense summer wildfires in southeastern Australia's alpine region burned more than 1.3 million ha. The Guthega Skink, Liopholis guthega, is an endangered lizard that is restricted to two geographically isolated alpine locations affected by these fires: Kosciuszko National Park in New South Wales, and the Bogong High Plains in Victoria. We investigated the long-term effects of fire on L. guthega populations through surveys of burned and unburned habitat on the Bogong High Plains. We found L. guthega selected specific microhabitats that are restricted on the Bogong High Plains. Their selection of less-vegetated microhabitats suggests that they may favor an early successional environment. We found retreat site selection differed between sites; at burned sites L. guthega burrowed preferentially under rocks, and at unburned sites comparatively more burrows were positioned at the base of shrubs. Our results suggest that in this species' Victorian range they may be more tolerant to fire than previously thought, likely because of the protection afforded by their burrows. However, our surveys of L. guthega populations from past records also suggest potential local extinctions. To determine the immediate and longer-term effects of intense fires on threatened species, it is important to have prefire data on species and prompt postfire assessments to obtain results applicable to management.

Recent studies on invasive species have led to the development of an apparent paradox when trying to explain how populations succeed after experiencing genetic bottlenecks in their new environments. Many introduced populations retain genetic diversity from multiple introduction events, but others that resulted from a single introduction event are expected to have low genetic diversity and low evolutionary potential. Introduced Black Spiny-Tailed Iguanas (Ctenosaura similis) on a barrier island (Keewaydin Island [KI]) in subtropical Florida are thought to be the result of a single introduction of a small founder group, although this population has expanded significantly since its founding in 1995. We investigated the presence of this genetic paradox by determining the genetic variation of this introduced population. We extracted DNA from muscle tissue samples (N = 21) and sequenced a region of the ND4 gene to allow for comparison with previously described native Ctenosaura populations. We documented a single haplotype from KI, which means this iguana population likely descended from a single introduction event and one geographic source population (Honduras). If this single haplotype represents an overall reduction in genetic diversity, then this population demonstrates that genetic variability is not always necessary for a species to become established in a new ecological range. This interpretation may have strong implications for invasive species management.

We studied diet, reproduction, and sexual dimorphism in Mabuya arajara (Arajara Skink; Scincidae) in a rainforest on the slopes of the Araripe Plateau, northeastern Brazil. Diet was composed mainly of arthropods, mostly termites, when considering both number (93.5%, n = 58) and volume (58.5%, n = 58). Mabuya arajara can be classified as a forager that uses intermediate foraging techniques, as do most of its congeners. Brood size of M. arajara ranged from two to nine neonates (4.8 ± 1.7), and larger females tended to produce larger broods. The period of parturition occurs between October and December. Adult females of M. arajara were larger and heavier than adult males. There was no significant difference between the body size of males and females, but there was a significant difference in body shape between sexes. The positive relationship between brood size and female size can be considered an important correlate of the sexual selection of bigger females in Mabuya and other South American lizards in general.

Northern Pine Snakes (Pituophis melanoleucus) are one of the few snakes that spend the winter in underground hibernacula that they excavate. We report the use of hibernacula by Pine Snakes from 1986 to 2012 in the New Jersey Pine Barrens. We determined whether philopatry to a specific hibernaculum varied as a function of age, sex, and location of the hibernaculum. Three hibernacula were occupied nearly continuously for 27 yr by 1 to 27 snakes each year. With known-age snakes (N = 120), captured mainly as hatchlings and 2-yr-olds, we found that 23% were always philopatric. Philopatry was related to age of last capture, sex, and capture location. Philopatry was higher for 1) females compared with males, 2) snakes at two solitary hibernacula compared with a hibernaculum complex, and 3) snakes 6 yr old or younger, compared with older snakes. Of hatchlings found hibernating, 24% used the same hibernation site the next year, and 38% were located at year 4 or later. The number of snakes that always used the same hibernation site declined with the age of last capture. Snakes that entered hibernacula as hatchlings were found more often than those that entered as 2-yr-olds. For the seven snakes that were 14 yr or older, females were found 64–86 % of the time, whereas males were found 15 to 50% of the time. Understanding the behavior and habitat requirements of snakes during different seasons is central to life-history analysis and for conserving viable populations.

Miniature toadlet species of the genus Brachycephalus are endemic to the Atlantic rain forest of Brazil, and little is known about their biology and ecology. We present data on the diet of Brachycephalus pitanga in both rainy and dry seasons and compare the diet to the prey available in leaf litter. We analyzed the stomach contents of 30 specimens: 20 of them collected in the rainy season and 10 in the dry season. Two hundred fifty-nine prey were identified, including spiders, mites, collembolans, ants, hemipterans, dipterans, and coleopterans. In the leaf litter, we identified 1,056 potential prey—676 in the rainy season and 380 in the dry season—belonging to 11 categories, with mites, collembolans, and ants being the most common potential prey. Toadlets consumed a larger number of prey but less volume and less taxonomic diversity in dry season compared to the rainy season. In the rainy season, females ate a larger number of items and a greater diversity than males, but their niche breadths were very similar. The prey items ingested showed greater similarity to the available items in the dry season, with mites and larvae being consumed in greater proportions than expected. Stomach contents collected during the rainy season suggested a preference for collembolans and spiders. Our results represent the first information on the diet of B. pitanga and are compared to data available for related species.

As espécies de anuros miniaturizados do gênero Brachycephalus são endêmicas da Mata Atlântica do Brasil, e pouco se conhece da sua biologia e ecologia. No presente trabalho nós apresentamos dados sobre a dieta de Brachycephalus pitanga nas estações seca e chuvosa e os comparamos à disponibilidade de presas na serapilheira. Analisamos os conteúdos estomacais de 30 espécimes, 20 deles coletados na estação chuvosa e 10 na estação seca. Duzentos e cinqüenta e nove itens foram identificados, incluindo aranhas, ácaros, colêmbolos, formigas, hemípteros, dípteros e coleópteros. Na serapilheira nós identificamos 1,056 itens—676 na estação chuvosa e 380 na estação seca—pertencentes a 11 categorias, sendo ácaros, colêmbolos e formigas os itens mais freqüentes. Durante a estação seca os indivíduos consumiram um maior número de presas, mas em menor volume e diversidade. Na estação chuvosa, os indivíduos consumiram um menor número de presas, mas em maior volume e diversidade. Na estação chuvosa, as fêmeas consumiram um maior número de itens e em maior diversidade em comparação aos machos, mas a amplitude de nicho dos dois sexos foi similar. A ingestão de presas mostrou uma grande similaridade com os itens disponíveis na estação seca, sendo ácaros e larvas as categorias consumidas em maior proporção que o esperado. Na estação chuvosa, os indivíduos exibiram uma preferência por colêmbolos e aranhas. Nossos resultados são as primeiras informações sobre a dieta de Brachycephalus pitanga e foram comparados com os dados disponíveis para outras espécies próximas.

Eastern Spadefoots (Scaphiopus holbrookii) are probably one of the least-understood amphibian species in the United States. In New England, populations are localized and it is likely that some populations go undocumented because of the species' cryptic habits. We used passive integrated transponders (PIT tags) to monitor burrow emergence with the aid of continuously running, stationary (but portable) PIT tag readers. We monitored the activity of individual Eastern Spadefoots by placing circular antennae directly over burrows of PIT tag-implanted individuals. We monitored 18 Eastern Spadefoots from 1 to 84 nights in the spring, summer, and fall of 2009–2011. Our results indicate that, on average, Eastern Spadefoots emerged on 43% of the nights that they were monitored. Nights when Eastern Spadefoots emerged were warmer and more humid than nonemergence nights. Eastern Spadefoots were also much more likely to emerge on a given night if they had emerged the night before. Our results have improved the understanding of Eastern Spadefoot burrow-emergence patterns in the northeast region. Our findings may considerably enhance the prospect of employing nocturnal visual encounter surveys as a method for monitoring known, and detecting previously undocumented, populations of this species.

Aquatic and semiaquatic turtles use wetlands and thermally buffered soils to thermoregulate during the active season and to sustain body temperatures above freezing during overwintering. We deployed temperature data loggers during wintertime and summertime in wetlands occupied by Bog Turtles (Glyptemys muhlenbergii) in southwestern Virginia, United States, to contrast the temperatures of the wetland environment to turtle carapace temperatures over two field seasons. Temperature signatures were used to evaluate probable hibernation depth and the timing and cues of spring emergence. We measured soil temperature profiles during winter in saturated hibernacula and similar but unsaturated structures to evaluate the dependence of temperature on water-table depth. Mean daily turtle temperature (n = 16) during the coldest portion of two winters was 2.5°C (SE = 0.29), with one turtle experiencing 14 continuous days at temperatures between −1°C and 0°C when ambient temperatures dipped below −10°C. Water tables remained within 15 cm below the soil surface throughout both winters, preventing freezing temperatures for shallow-hibernating turtles. The date of first emergence differed by 15 d between the two study years, with both soil temperature and ambient temperature potentially serving as emergence cues. During summer activity, turtles alternated between periods of thermoregulation and thermoconformity by basking and accessing deep, thermally buffered saturated soil. The dependence of Bog Turtle body temperature on soil saturation and depth is important for understanding how hydrologic alteration in wetlands can affect Bog Turtle ecology.

The composition of Urodela assemblages is regulated by macro- and microclimatic conditions and by the interactions established between ecologically analogous species. Species of the North African Urodela are distributed unevenly; some species have large ranges whereas others occur in fragmented populations or in restricted ranges. We examined the niches occupied by these species to determine the factors that regulate their range patterns. The niches were examined at two spatial levels; regionally, using climatic and vegetation cover data, and locally by studying the selection of aquatic habitats. Our results indicate that Salamandra algira (North African fire salamander) and North African Pleurodeles species are segregated along a thermal and vegetation cover axis, although with considerable overlap. The fragmentation observed in the distribution of the North African Urodela is caused by prevailing arid conditions in the region. The three Pleurodeles species appear under similar climate conditions and mostly use temporary ponds to breed. There is some overlap comparing species from both genera in the selection of breeding habitats, but the North African Pleurodeles species occur in ponds with higher water temperatures than do S. algira. Preserving temporary ponds, streams, and springs is essential for conserving these species, particularly under the semiarid conditions that favor the fragmentation of their populations.

La composition des assemblages des urodèles est régulée par les conditions macro- et microclimatiques et par les interactions établies entre des espèces écologiquement proches. Les espèces d'urodèles d'Afrique du Nord sont inégalement réparties: certaines espèces ont de grandes aires de répartition, tandis que d'autres présentent des populations fragmentées ou à répartition restreinte. Dans cet article, nous avons examiné les niches occupées par ces espèces afin de déterminer les facteurs qui régulent leurs patterns de distribution. Les niches ont été examinées à deux niveaux spatiaux: au niveau régional, en utilisant des données climatiques et des données portant sur le couvert végétal, et localement, par l'étude de la sélection des habitats aquatiques. Nos résultats indiquent que Salamandra algira et les espèces Nord africaines de Pleurodeles sont séparés par des axes relatifs à la température et à la structure de la végétation avec un chevauchement considérable. La fragmentation observée dans la distribution des urodèles de l'Afrique du Nord est due aux conditions arides régnant dans la région. Les trois espèces de Pleurodeles apparaissent dans des conditions climatiques similaires et utilisent principalement des mares temporaires pour se reproduire. En comparant les espèces des deux genres, on observe un certain chevauchement dans la sélection des habitats de reproduction, toutefois les Pleurodeles d'Afrique du Nord se reproduisent dans des étangs dont la température de l'eau est plus élevée que ceux de S. algira. Préserver les mares temporaires, les ruisseaux, et des sources est essentiel pour la conservation de ces espèces, en particulier dans les conditions semi-arides qui favorisent l'isolement de leurs populations.

Most previous studies of clinging ability in Anolis lizards have focused on how toepads adhere to smooth, flat surfaces; yet lizards in nature use a wide variety of substrates ranging from smooth to rough and narrow to broad. I used an ecologically relevant measure of performance to determine the effects of hind-limb length and substrate diameter on clinging ability for two species of Anolis lizards from the British Virgin Islands. Clinging force was greater on the 12-mm smooth, wooden dowel compared to the 33-mm one for both species. Male Anolis cristatellus had considerably larger hind limbs than female A. cristatellus and both sexes of Anolis stratulus, and consequently performed substantially better on both dowel diameters. Results suggest two important components of clinging ability on cylindrical substrates: first, the ability of lizards to reach around and interlock their limbs with the substrate increases with longer limbs and narrower substrates; and second, the limb strength to maintain a grip on the dowel when limbs wrap fully around and the ability to apply compressive force when limbs wrap only partially around the dowel. These abilities are likely related to muscle size (e.g., cross-sectional area) and may be correlated with limb length. Further studies to understand how multiple morphological traits and different substrates affect clinging performance will contribute to a better understanding of this morphology-performance-habitat use relationship.

Studies about copulatory organs in Squamata were restricted to the morphology of hemipenes until Böhme reported homologous paired structures in females of a species of Varanus, which he called hemiclitores. We report the presence of hemiclitores in females of Phymaturus and of two species of Liolaemus and describe observations on the interspecific variation in hemipenis morphology in Phymaturus. Phymaturus and Liolaemus belong to Liolaemidae, a species-rich family of lizards; research about hemipenis morphology is scarce and limited to a few species of those genera. We found the retractor clitoridis magnus in all of the species analyzed; however, the transverse penis was not present in all of them. The general structure of hemiclitores of Phymaturus and Liolaemus females resembled that described for other squamate species; they were smaller than hemipenes and exhibited a sulcus spermaticus. The variation found in different features of these organs (shape, size, pigmentation), as well as the general morphology of hemipenes, should be studied more extensively in more species. These results contribute to the description of structures that are still poorly known in the large groups of Squamata and support the idea that hemiclitores should be considered an apomorphy of Squamata.

Los estudios de los órganos copuladores de Squamata estuvieron restringidos a la morfología de los hemipenes hasta que Böhme reportó la presencia de estructuras pareadas homologas a la de los machos, a las que llamó hemiclitoris. Nosotros reportamos la presencia de hemiclitoris en las hembras del género Phymaturus y en dos especies del género Liolaemus así como observaciones sobre la variación interespecífica en la morfología de los hemipenes de Phymaturus. Phymaturus y Liolaemus pertenecen a Liolaemidae, una familia de lagartijas muy diversa, para los cuales las investigaciones en la morfología de los hemipenes son escasas y limitadas a unas pocas especies. En todas las especies revisadas encontramos el músculo retractor clitoridis magnus pero no el transversus penis. La estructura general de los hemiclitoris de las hembras de Phymaturus y Liolaemus, se asemeja a la descrita para otras especies de Squamata; son más pequeñas que los hemipenes y exhiben un sulcus spermaticus. La variación encontrada en diferentes características de estos órganos (forma, tamaño, pigmentación), así como la morfología general de hemipenes, debe ser estudiada más extensamente incluyendo un mayor número de especies. Estos resultados contribuyen con el reporte y la descripción de estructuras que son aún poco conocidas en los grandes grupos de Squamata, y soporta la idea que los hemiclitoris deben ser consideramos una apomorfia de Squamata.

Two cranial osteoderms and a maxilla assigned to Heloderma suspectum (Squamata, Helodermatidae) were recovered from the 111 Ranch fossil locality, San Simon Valley, Graham County, southeastern Arizona. A minimum age of the deposits and fossils is approximately 2.7–2.4 million years ago, latest Blancan Land Mammal Age, spanning the Pliocene-Pleistocene boundary. The presence of a pronounced deep venom grove and a tooth count of eight indicate that the maxilla belongs to Heloderma and not the closely related and extinct Lowesaurus or Eurheloderma. The highly reduced nasolacrimal fossa and the shortened projection of the maxillary lappet on the fossil agree with the condition in H. suspectum and not in Heloderma horridum. During this transition time, the locality was a mosaic grassland–woodland ecosystem with open water and riparian niches occupied with grazing and browsing mammals.

We investigate the relationship between Rana coreana and Rana kunyuensis using morphological and molecular data. Morphological comparisons showed these two species to be identical in terms of body measurements and qualitative characteristics. Phylogenetic analyses found that R. kunyuensis and R. coreana are nested within a single clade and exhibited low divergence across several mitochondrial and nuclear genes. All evidence indicates that R. kunyuensis and R. coreana are the same species, making R. kunyuensis a junior synonym of R. coreana. This study stresses the importance of comprehensive taxon sampling, especially in neighboring countries.

Gymnophionan amphibians are characterized mainly by having elongated bodies and lack of limbs and are poorly known because of their secretive life habits. Most species are fossorial, although some are aquatic or semiaquatic. We describe a new species of semiaquatic caecilian, genus Chthonerpeton, from a transition area between the Caatinga and Cerrado biomes, along the coastal vegetation of the State of Piauí, northeastern Brazil. The new species is very similar to Chthonerpeton perissodus and Chthonerpeton noctinectes in annular counts but differs in number of cloacal denticles, color pattern, position of tentacle aperture, and number of teeth.

There is ongoing uncertainty regarding the taxonomic status of Painted Turtles (genus Chrysemys). Most recently, a phylogenetic analysis of the mitochondrial DNA control region (mtCR) resulted in the elevation of a subspecies to the species level, resulting in two species being tentatively, but not universally, accepted: Chrysemys dorsalis and C. picta, the latter encompassing the three remaining subspecies. Here, we used expanded range-wide sampling and character data from PAX-P1 nuclear intron (n = 127) and mtCR (n = 259) to further investigate taxonomic uncertainty and paleogeography of Painted Turtles. We found five mtCR characters that distinguished C. dorsalis from C. picta; no such evidence was found in PAX-P1. Chrysemys dorsalis formed a monophyletic group in the reconstructed phylogenetic trees, whereas there was no genetic evidence for the distinctiveness of the three C. picta subspecies. The mtCR network showed C. dorsalis and C. p. bellii to each form relatively distinct clusters, whereas no clustering by morphotype was found in the PAX-P1 network. Lower levels of haplotypic diversity across the range of C. p. bellii are consistent with recent postglacial expansion to the west; however, observed mismatch distributions were multimodal, which does not indicate population expansion. Overall, the addition of nuclear DNA character data and expanded sampling support the tentative designation of C. dorsalis and C.picta (encompassing C. p. picta, C. p. bellii, and C. p. marginata) as separate species. Yet, lack of accompanying morphological data and potential for oversplitting due to targeting only individuals within the core of morphotype ranges suggests that further study is warranted.

The nominal species Typhlops silus has been used consistently as a junior synonym of the Typhlops lumbricalis. In this review, the current taxonomic status of T. silus is resolved by means of morphological characters and comparisons among blind snakes of the Typhlops lumbricalis species group from the Bahama Islands, Cuba, and Hispaniola. The results support the resurrection of the T. silus, restricted to eastern provinces of Cuba. A paratype (KU 47470) is not preliminarily referred to this name in this paper because the type series of the T. silus could comprises two species. This specimen differs in the head scutellation from the holotype and a second paratype (KU 47471). A redescription of T. silus (including several additional specimens) and a new key to the West Indian species of the Typhlops lumbricalis species group are provided. Typhlops silus is characterized by its small size as well as a rounded snout, narrow to broad oval rostral in dorsal view, preocular contacting third supralabial only, and low middorsal scale counts (<300), 20 scale rows anteriorly reducing to 18 posteriorly at around midbody.