High phenotypic plasticity at the dawn of the eosauropterygian radiation.

The initial radiation of Eosauropterygia during the Triassic biotic recovery represents a key event in the dominance of reptiles secondarily adapted to marine environments. Recent studies on Mesozoic marine reptile disparity highlighted that eosauropterygians had their greatest morphological diversity during the Middle Triassic, with the co-occurrence of Pachypleurosauroidea, Nothosauroidea and Pistosauroidea, mostly along the margins of the Tethys Ocean. However, these previous studies quantitatively analysed the disparity of Eosauropterygia as a whole without focussing on Triassic taxa, thus limiting our understanding of their diversification and morphospace occupation during the Middle Triassic. Our multivariate morphometric analyses highlight a clearly distinct colonization of the ecomorphospace by the three clades, with no evidence of whole-body convergent evolution with the exception of the peculiar pistosauroid Wangosaurus brevirostris, which appears phenotypically much more similar to nothosauroids. This global pattern is mostly driven by craniodental differences and inferred feeding specializations. We also reveal noticeable regional differences among nothosauroids and pachypleurosauroids of which the latter likely experienced a remarkable diversification in the eastern Tethys during the Pelsonian. Our results demonstrate that the high phenotypic plasticity characterizing the evolution of the pelagic plesiosaurians was already present in their Triassic ancestors, casting eosauropterygians as particularly adaptable animals.

Genomic analysis and adaptive evolution of the RIG-I-like and NOD-like receptors in reptiles.

Pattern recognition receptors (PRRs) play a crucial role in the host's innate immune system. Among the PPRs, the RIG-I-like (RLRs) and NOD-like receptors (NLRs) are two important subgroups. To understand the role of RLRs (RIG-I, MDA5, LGP2) and NLRs (NOD1, NLRC3, NLRX1, NOD2) in reptilian evolution, we identified six genes from reptilian genomes. A total of 168 putative genes were identified from 28 reptile species, including 141 intact genes, 25 partial genes and two pseudogenes. Interestingly, the NOD2 gene was absent in all reptile species. Phylogenetic results showed that all genes were divided into four major clades corresponding to their traditional taxonomic groups, indicating that these genes are conserved in reptiles. Evolutionary analyses detected positive selection in six genes. Most of the positively selected sites (50/76) were located in known functional domains, reflecting their critical and particular contributions to host defense during reptilian evolution. Branch model analysis showed that NLRs were under different evolutionary forces, while the RLRs were not, suggesting that semiaquatic species and terrestrial species faced different environmental pathogens, leading to different adaptations. Moreover, the positively selected sites identified in MDA5 using the branch-site model among semiaquatic reptiles, suggested their involvement in adaptation to semiaquatic environments.

Premaxillary crest variation within the Wukongopteridae (Reptilia, Pterosauria) and comments on cranial structures in pterosaurs

ABSTRACT Cranial crests show considerable variation within the Pterosauria, a group of flying reptiles that developed powered flight. This includes the Wukongopteridae, a clade of non-pterodactyloids, where the presence or absence of such head structures, allied with variation in the pelvic canal, have been regarded as evidence for sexual dimorphism. Here we discuss the cranial crest variation within wukongopterids and briefly report on a new specimen (IVPP V 17957). We also show that there is no significant variation in the anatomy of the pelvis of crested and crestless specimens. We further revisit the discussion regarding the function of cranial structures in pterosaurs and argue that they cannot be dismissed a priori as a valuable tool for species recognition.

An exceptional fossil skull from South America and the origins of the archosauriform radiation.

Birds, dinosaurs, crocodilians, pterosaurs and their close relatives form the highly diverse clade Archosauriformes. Archosauriforms have a deep evolutionary history, originating in the late Permian, prior to the end-Permian mass extinction, and radiating in the Triassic to dominate Mesozoic ecosystems. However, the origins of this clade and its extraordinarily successful body plan remain obscure. Here, we describe an exceptionally preserved fossil skull from the Lower Triassic of Brazil, representing a new species, Teyujagua paradoxa, transitional in morphology between archosauriforms and more primitive reptiles. This skull reveals for the first time the mosaic assembly of key features of the archosauriform skull, including the antorbital and mandibular fenestrae, serrated teeth, and closed lower temporal bar. Phylogenetic analysis recovers Teyujagua as the sister taxon to Archosauriformes, and is congruent with a two-phase model of early archosauriform evolution, in response to two mass extinctions occurring at the end of the Guadalupian and the Permian.

Contributions to the knowledge of amphibians and reptiles from Volta Grande do Xingu, northern Brazil / Contribuições para o conhecimento de anfíbios e répteis da Volta Grande do Xingu, norte do Brasil

Abstract The region of Volta Grande do Xingu River, in the state of Pará, presents several kinds of land use ranging from extensive cattle farming to agroforestry, and deforestation. Currently, the Belo Monte Hydroelectric Power Plant affects the region. We present a checklist of amphibians and reptiles of the region and discuss information regarding the spatial distribution of the assemblies based on results of Environmental Programmes conducted in the area. We listed 109 amphibian (Anura, Caudata, and Gymnophiona) and 150 reptile (Squamata, Testudines, and Crocodylia) species. The regional species richness is still considered underestimated, considering the taxonomic uncertainty, complexity and cryptic diversity of various species, as observed in other regions of the Amazon biome. Efforts for scientific collection and studies related to integrative taxonomy are needed to elucidate uncertainties and increase levels of knowledge of the local diversity.

Resumo A região da Volta Grande no Rio Xingu, localizada no estado do Pará, apresenta várias frentes de exploração que vão desde a criação animal até área de cultivo, resultando no desmatamento de fragmentos florestais. Atualmente a região está sendo impactada pela implantação da Usina Hidrelétrica de Belo Monte. A partir de dados obtidos através dos Programas de Monitoramento Ambiental realizados na área de influência da UHE Belo Monte, apresentamos uma listagem das espécies de anfíbios e répteis, com comentários sobre a distribuição espacial das assembleias. Foram catalogados 109 espécies de anfíbios (Anura, Caudata e Gymnophiona) e 150 de répteis (Squamata, Testudines e Crocodylia). Considerando as incertezas taxonômicas, a complexidade e a diversidade críptica de várias espécies, a riqueza regional ainda continua subestimada, assim como observado em outras regiões da Amazônia. Esforços direcionados ao aproveitamento científico e estudos que contemplem a taxonomia integrativa são necessários para elucidar as incertezas e aumentar o nível de conhecimento sobre a diversidade da região.

Contributions to the knowledge of amphibians and reptiles from Volta Grande do Xingu, northern Brazil / Contribuições para o conhecimento de anfíbios e répteis da Volta Grande do Xingu, norte do Brasil

The region of Volta Grande do Xingu River, in the state of Pará, presents several kinds of land use ranging from extensive cattle farming to agroforestry, and deforestation. Currently, the Belo Monte Hydroelectric Power Plant affects the region. We present a checklist of amphibians and reptiles of the region and discuss information regarding the spatial distribution of the assemblies based on results of Environmental Programmes conducted in the area. We listed 109 amphibian (Anura, Caudata, and Gymnophiona) and 150 reptile (Squamata, Testudines, and Crocodylia) species. The regional species richness is still considered underestimated, considering the taxonomic uncertainty, complexity and cryptic diversity of various species, as observed in other regions of the Amazon biome. Efforts for scientific collection and studies related to integrative taxonomy are needed to elucidate uncertainties and increase levels of knowledge of the local diversity.

A região da Volta Grande no Rio Xingu, localizada no estado do Pará, apresenta várias frentes de exploração que vão desde a criação animal até área de cultivo, resultando no desmatamento de fragmentos florestais. Atualmente a região está sendo impactada pela implantação da Usina Hidrelétrica de Belo Monte. A partir de dados obtidos através dos Programas de Monitoramento Ambiental realizados na área de influência da UHE Belo Monte, apresentamos uma listagem das espécies de anfíbios e répteis, com comentários sobre a distribuição espacial das assembleias. Foram catalogados 109 espécies de anfíbios (Anura, Caudata e Gymnophiona) e 150 de répteis (Squamata, Testudines e Crocodylia). Considerando as incertezas taxonômicas, a complexidade e a diversidade críptica de várias espécies, a riqueza regional ainda continua subestimada, assim como observado em outras regiões da Amazônia. Esforços direcionados ao aproveitamento científico e estudos que contemplem a taxonomia integrativa são necessários para elucidar as incertezas e aumentar o nível de conhecimento sobre a diversidade da região.

Riqueza de herpetofauna de la Finca Universitaria San Julián, Patulul, Suchitepéquez, Guatemala / Herpetofaunal richness of San Julian Universitary Farm, Patulul, Suchitepequez, Guatemala

Aprovechando actividades de docencia de la Unidad de Vida Silvestre de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad de San Carlos de Guatemala, se investigó la riqueza de herpetofauna de la Finca Universitaria San Julián, en Patulul, Suchitepéquez. Se emplearon 3 métodos: (1) captura/avistamiento de especímenes, (2) investigación social, (3) investigación documental. Se recorrió repetidamente un transecto de 4.5 km de longitud a través del agro paisaje de la finca. Los recorridos del transecto abarcaron un período de 10 años (2003-2013), a razón de seis sesiones por año. Cada sesión de campo consistió en un recorrido diurno y un recorrido nocturno del transecto. Se invirtieron aproximadamente 3 hr en cada recorrido diurno y 4 hr en cada recorrido nocturno. El tiempo acumulado de búsqueda fue de 420 hr-transecto. Se recorrió el equivalente a 540 km abarcando elevaciones entre 447 y 550 msnm. En cada sesión de campo participaron entre 3 y 10 personas. Tres excazadores de la finca fueron entrevistados. Se analizaron publicaciones sobre distribución de la herpetofauna para Guatemala. Se generaron dos listas que suman 97 especies. Se discute la calidad y el significado de los datos generados.

The herpetofaunal richness of San Julian Universitary Farm (FUSJ), in Patulul, Suchitepequez, Guatemala, was investigated using three methods: (1) Capture/sighting of specimens, (2) social inquiry and (3) desk research. The field work was distributed over a 10 year period (2003-2013) at a rate of six fieldwork sessions each year. A 4.5 km long transect extending through the agricultural landscape of the farm was run repeatedly. Each fieldwork session included diurnal and nocturnal travels. The accumulated search time was 420 hr-transect. The equivalent to 337.5 of accumulated miles were traveled, including elevations between 1490 and 1833 feet above sea level. Three former hunters were interviewed and asked to identify species they think are present at the FUSJ. Published data were reviewed to determine which species were expected to occur in San Julian. Two lists (amphibians and reptiles) totaling 97 species (including 95 expected, 38 found and 2 not expected) was generated. The quality and significance of our data is discussed.

New clade of enigmatic early archosaurs yields insights into early pseudosuchian phylogeny and the biogeography of the archosaur radiation.

BACKGROUND: The origin and early radiation of archosaurs and closely related taxa (Archosauriformes) during the Triassic was a critical event in the evolutionary history of tetrapods. This radiation led to the dinosaur-dominated ecosystems of the Jurassic and Cretaceous, and the high present-day archosaur diversity that includes around 10,000 bird and crocodylian species. The timing and dynamics of this evolutionary radiation are currently obscured by the poorly constrained phylogenetic positions of several key early archosauriform taxa, including several species from the Middle Triassic of Argentina (Gracilisuchus stipanicicorum) and China (Turfanosuchus dabanensis, Yonghesuchus sangbiensis). These species act as unstable 'wildcards' in morphological phylogenetic analyses, reducing phylogenetic resolution. RESULTS: We present new anatomical data for the type specimens of G. stipanicicorum, T. dabanensis, and Y. sangbiensis, and carry out a new morphological phylogenetic analysis of early archosaur relationships. Our results indicate that these three previously enigmatic taxa form a well-supported clade of Middle Triassic archosaurs that we refer to as Gracilisuchidae. Gracilisuchidae is placed basally within Suchia, among the pseudosuchian (crocodile-line) archosaurs. The approximately contemporaneous and morphologically similar G. stipanicicorum and Y. sangbiensis may be sister taxa within Gracilisuchidae. CONCLUSIONS: Our results provide increased resolution of the previously poorly constrained relationships of early archosaurs, with increased levels of phylogenetic support for several key early pseudosuchian clades. Moreover, they falsify previous hypotheses suggesting that T. dabanensis and Y. sangbiensis are not members of the archosaur crown group. The recognition of Gracilisuchidae provides further support for a rapid phylogenetic diversification of crown archosaurs by the Middle Triassic. The disjunct distribution of the gracilisuchid clade in China and Argentina demonstrates that early archosaurs were distributed over much or all of Pangaea although they may have initially been relatively rare members of faunal assemblages.

Looking for the bird Kiss: evolutionary scenario in sauropsids.

BACKGROUND: The neuropeptide Kiss and its receptor KissR are key-actors in the brain control of reproduction in mammals, where they are responsible for the stimulation of the activity of GnRH neurones. Investigation in other vertebrates revealed up to 3 Kiss and 4 KissR paralogs, originating from the two rounds of whole genome duplication in early vertebrates. In contrast, the absence of Kiss and KissR has been suggested in birds, as no homologs of these genes could be found in current genomic databases. This study aims at addressing the question of the existence, from an evolutionary perspective, of the Kisspeptin system in birds. It provides the first large-scale investigation of the Kisspeptin system in the sauropsid lineage, including ophidian, chelonian, crocodilian, and avian lineages. RESULTS: Sauropsid Kiss and KissR genes were predicted from multiple genome and transcriptome databases by TBLASTN. Phylogenetic and syntenic analyses were performed to classify predicted sauropsid Kiss and KissR genes and to re-construct the evolutionary scenarios of both gene families across the sauropsid radiation.Genome search, phylogenetic and synteny analyses, demonstrated the presence of two Kiss genes (Kiss1 and Kiss2 types) and of two KissR genes (KissR1 and KissR4 types) in the sauropsid lineage. These four genes, also present in the mammalian lineage, would have been inherited from their common amniote ancestor. In contrast, synteny analyses supported that the other Kiss and KissR paralogs are missing in sauropsids as in mammals, indicating their absence in the amniote lineage. Among sauropsids, in the avian lineage, we demonstrated the existence of a Kiss2-like gene in three bird genomes. The divergence of these avian Kiss2-like sequences from those of other vertebrates, as well as their absence in the genomes of some other birds, revealed the processes of Kiss2 gene degeneration and loss in the avian lineage. CONCLUSION: These findings contribute to trace back the evolutionary history of the Kisspeptin system in amniotes and sauropsids, and provide the first molecular evidence of the existence and fate of a Kiss gene in birds.

Mortalidad de vertebrados en la carretera Guanare-Guanarito, estado Portuguesa, Venezuela / Vertebrate mortality in the Guanare-Guanarito road, Portuguesa state, Venezuela

Roads directly or indirectly affect the structure, dynamics and function of ecosystems that they traverse. Most studies on the effect of roads on wildlife focus on the evaluation of mortality of vertebrates by vehicle collisions. Despite the extensive road network that exists in Venezuela, studies of wildlife mortality in them are scarce. In this paper, we analyzed the temporal and spatial pattern of vertebrate’s collisions along the road Guanare-Guanarito, in Portuguesa state. We travelled 26 times between these towns (74km) to localize dead vertebrates, at a speed of 50-60km/h. of those trips were conducted from March 13 to October 26, 2010, and 10 additional trips from December 7, 2009 to December 14, 2010; these ones, with the aim to include months and seasons that were insufficiently sampled during the first period. The elapsed time between trips varied from 14 to 37 days. The total distance traveled was 1 924km. Dead animals found amounted 464 individuals, 66 of them were birds (25 identified species), 130 mammals (15 species) and 268 reptiles (18 species). The species with the highest number of individuals were the snake Leptodeira annulata (n=119), the oppossum Didelphis marsupialis (n=39) and the spectacled caiman Caiman crocodilus (n=33). Excluding domestic animals, the rate of road-killed vertebrates was 0.2282indiv./km, a figure 28.3% higher than previous studies in the same road. Changes in the relative number of collisions for some species, respect to the numbers reported 20 years ago, were linked to the increase in traffic flow and changes in land use. Road segments with collision rates higher than expected by chance were identified. Collition by cars may be the principal cause of mortality for species like the tamandua (Tamandua tetradactyla) and the giant anteater (Myrmecophaga tridactyla), the last considered a vulnerable species. Some basic measures are proposed to reduce wildlife mortality on the road.

Uno de los aspectos más investigados en relación a la “ecología de la carretera” es el atropellamiento de vertebrados silvestres. Se evaluó la distribución espacial y temporal de los atropellos de vertebrados en la carretera Guanare-Guanarito, estado Portuguesa, Venezuela. Desde 2008 hasta el 2010 se realizaron 26 viajes en carro a lo largo de 74km, a 50-60km/h, para un total recorrido de 1 924km. Se encontraron 464 animales muertos: 66 aves (25 especies), 130 mamíferos (15 especies) y 268 reptiles (18 especies). La serpiente Leptodeira annulata (n=119), el rabipelado Didelphis marsupialis (n=39) y la baba Caiman crocodilus (n=33) fueron las especies con mayor frecuencia de atropellos. Excluyendo a los animales domésticos, se localizaron 0.2282indviv./km; cifra 28.30% mayor que la reportada en estudios previos en la misma vía. Los cambios en la frecuencia relativa de atropellos de algunas especies con respecto a los reportados hace 20 años, se relacionan con el incremento en el flujo vehicular y por modificaciones en el uso de la tierra. Se identificaron segmentos donde el número de individuos atropellados supera al esperado por azar. Los atropellos pudieran ser la principal causa de mortalidad para especies como el oso melero (Tamandua tetradactyla) y el oso hormiguero (Myrmecophaga tridactyla), esta última considerada como una especie vulnerable. Se recomiendan algunas medidas básicas para disminuir la mortalidad de fauna en la carretera.

The role of microhabitat in predation on females with alternative dorsal patterns in a small Costa Rican anole (Squamata: Dactyloidae) / Papel del microhábitat en la depredación de hembras con patrones dorsales alternativos en una pequeña lagartija de Costa Rica (Squamata: Dactyloidae)

Predation is one of the major selective agents influencing evolution of color patterns. Cryptic color patterns decrease detection probability by predators, but their concealing function depends on the background against which patterns are seen; therefore, habitat use and color patterns are tightly linked. in many anole species, females exhibit variation in dorsal color patterns; the drab and perhaps cryptic colors of the patterns suggest a predator avoidance function behind this polymorphism. We tested whether these different color patterns experience different predation rates depending on their micro- habitat. We expected each pattern to form at least one optimal combination with a typically used micro-habitat that would result in lower predation compared to other morphs in the same micro-habitat. We tested this hypothesis for anoles at La Selva, Costa Rica, using clay models resembling a common species at this site: Norops humilis. The first experiment tested for variation in predation on various substrates. We included leaf litter, live leaves, and two size classes of woody stems, using 44 models for each pattern substrate combination. A second experiment tested effects of perch height (10 and 60cm) and diameter (<2cm and >5cm), with 50 models for each pattern perch combination. We found differences in predation rates between the morphs depending on their micro-habitat. Specifically, the striped morph had a significant advantage over the others on green leaves. in the second experiment, striped morphs showed significantly lower predation on low than on high perches, irrespective of perch diameter. Reticulated models had an advantage over other morphs on thin stems for the first experiment, where models were placed about 60cm high. Diameter did not have a significant effect on predation for reticulated morphs when height classes were combined. Dotted models did not experience an advantage over the other morphs in any of the treatments. in leaf litter and on thick perches no morph had any advantage over another, and leaf litter predation rates were generally low. These results support a role for predation in maintaining multiple female morphs within small Costa Rican anoles, such as N. humilis.

En los animales, los patrones dorsales de coloración a menudo se asocian con la protección contra la depredación. Con el fin de analizar el papel que tienen los micro-hábitat en la depredación de lagartijas hembras que presentan variaciones en los patrones de coloración dorsal (colores grises, crípticos), se realizó en la Estación Biológica La Selva, Costa Rica un estudio con el objetivo de comprobar si los patrones de diferentes colores provocan cambios en las tasas de depredación en función de a su micro-hábitat; se esperaba que cada patrón formara una combinación óptima utilizando el micro-habitat y que permitiera de esta manera reducir los niveles de depredación. Para evidenciar esta hipótesis se utilizaron modelos de arcilla que asemejan a la especie Norops humilis propia del lugar. Se realizaron dos estudios, el primero analizó modelos colocados en cuatro sustratos diferentes: hojarasca, hojas vivas y dos clases de tamaño de tallos leñosos, los cuales representaban cada hábitat donde es posible observar esta especie. Un segundo experimento estudió el efecto de la altura y el diámetro de la percha en la depredación, para ello se colocaron los modelos sobre tallos de diferentes alturas y diámetros. Fue posible observar en el primer experimento que el morfo rayado tuvo una ventaja significativa sobre los demás morfos en las hojas verdes y que los modelos reticulados tuvieron una ventaja sobre otros morfos en tallos delgados. El segundo estudio mostró que los morfos rayados tienen una tasa de depredación baja en perchas altas, independientemente del diámetro de la percha. Fue posible comprobar que los morfos punteados no experimentaron ventaja sobre otros morfos en ninguno de los dos estudios.

Cornification in reptilian epidermis occurs through the deposition of keratin-associated beta-proteins (beta-keratins) onto a scaffold of intermediate filament keratins.

The isolation of genes for alpha-keratins and keratin-associated beta-proteins (formerly beta-keratins) has allowed the production of epitope-specific antibodies for localizing these proteins during the process of cornification epidermis of reptilian sauropsids. The antibodies are directed toward proteins in the alpha-keratin range (40-70 kDa) or beta-protein range (10-30 kDa) of most reptilian sauropsids. The ultrastructural immunogold study shows the localization of acidic alpha-proteins in suprabasal and precorneous epidermal layers in lizard, snake, tuatara, crocodile, and turtle while keratin-associated beta-proteins are localized in precorneous and corneous layers. This late activation of the synthesis of keratin-associated beta-proteins is typical for keratin-associated and corneous proteins in mammalian epidermis (involucrin, filaggrin, loricrin) or hair (tyrosine-rich or sulfur-rich proteins). In turtles and crocodilians epidermis, keratin-associated beta-proteins are synthesized in upper spinosus and precorneous layers and accumulate in the corneous layer. The complex stratification of lepidosaurian epidermis derives from the deposition of specific glycine-rich versus cysteine-glycine-rich keratin-associated beta-proteins in cells sequentially produced from the basal layer and not from the alternation of beta- with alpha-keratins. The process gives rise to Oberhäutchen, beta-, mesos-, and alpha-layers during the shedding cycle of lizards and snakes. Differently from fish, amphibian, and mammalian keratin-associated proteins (KAPs) of the epidermis, the keratin-associated beta-proteins of sauropsids are capable to form filaments of 3-4 nm which give rise to an X-ray beta-pattern as a consequence of the presence of a beta-pleated central region of high homology, which seems to be absent in KAPs of the other vertebrates.

Herpetofauna of Núcleo Experimental de Iguaba Grande, Rio de Janeiro state, Brazil / Herpetofauna do Núcleo Experimental de Iguaba Grande-Rio de Janeiro, Brasil

The Atlantic Rain forest, which is considered the second largest pluvial forest in the American continent, has had an estimated 93% of its original area destroyed. Although studies concerning the herpetofaunal diversity in this biome have been intensified in the past years, its diversity is still underestimated. The Nucleo Experimental de Iguaba Grande (NEIG) is included in an Environmental Protection Area (APA de Sapeatiba) in the Iguaba Grande municipality, Rio de Janeiro state, Brazil (22º 51' S and 42º 10' W). The goal of this study was to conduct an inventory of the reptile and amphibian species that occur in this area between July 2008 and December 2009. We recorded 19 species of amphibians (18 anurans and one caecilian) and 15 species of reptiles (three lizards, 11 snakes and one amphisbaenian). Leptodactylus latrans and L. mystacinus had the highest capture rates among amphibians captured, and among reptiles, Ameiva ameiva, Hemidactylus mabouia and Mabuya agilis had the highest capture rates. Rarefaction curves for both amphibians and reptiles did not reach the asymptote, indicating that the species richness in the NEIG is still underestimated.

A Floresta Atlântica é considerada a segunda maior floresta pluvial tropical do continente americano, embora seja estimado que mais de 93% de sua cobertura original tenha sido destruída. Estudos sobre a diversidade da herpetofauna da Mata Atlântica têm-se intensificado nos últimos anos, embora o conhecimento sobre a diversidade herpetofaunística desse bioma ainda seja considerado subestimado. O Núcleo Experimental de Iguaba Grande (22º 51' S and 42º 10' W) está inserido na Área de Proteção Ambiental de Sapeatiba (APA de Sapeatiba), no município de Iguaba Grande, Estado do Rio de Janeiro, Brasil. Objetivou-se, nesta pesquisa, realizar um levantamento das espécies de anfíbios e répteis de ocorrência nesta área, no período de julho de 2008 a dezembro de 2009. Foram registradas 19 espécies de anfíbios (18 anuros e uma cecília) e 15 espécies de répteis (três lagartos, 11 serpentes e um anfisbenídeo). As espécies Leptodactylus latrans e L. mystacinus representaram as maiores taxas de captura dentre as espécies de anfíbios capturados, enquanto que, para répteis, as maiores taxas de captura foram obtidas para Ameiva ameiva, Hemidactylus mabouia e Mabuya agilis. A curva de rarefação tanto para anfíbios quanto para répteis não atingiu a assíntota, indicando que a riqueza da área ainda está subestimada.

Unraveling the influences of soft-tissue flipper development on skeletal variation using an extinct taxon.

Adaptation to an aquatic habitat results in dramatic changes in tetrapod limb morphology as limbs take on the roles of propulsion and steering and lose their weight-bearing function. Changes include enclosure of the limb in a soft-tissue flipper and proportional lengthening of the distal limb, often accomplished through the addition of skeletal elements (hyperphalangy). The flipper structure itself and changes to the developmental architecture permitting hyperphalangy are hypothesized to increase observed limb variation, based on a cetacean model. These hypotheses are examined in the ichthyosaurs Stenopterygius and Mixosaurus. Hyperphalangy combined with high levels of variation in phalangeal counts were observed in both genera. The amount of variation was not proportional to the number of phalanges in a digit, but was related to functional digit length. In addition, qualitative variants were catalogued in both genera. Polyphalangy, phalangeal fusion, and additional ossifications in the zeugopodial row were not observed in Mixosaurus, but were common in Stenopterygius, even though both genera exhibited a similar degree of hyperphalangy. These results suggest that while the flipper structure and processes resulting in hyperphalangy may increase observed variation in phalangeal counts, these factors are unlikely to be causing high levels of qualitative variation in ichthyosaurs. Patterns of variation in ichthyosaur limbs, and thus variability, are unique to species but can change over evolutionary time.

Rampant horizontal transfer of SPIN transposons in squamate reptiles.

Transposable elements (TEs) are highly abundant in the genome and capable of mobility, two properties that make them particularly prone to transfer horizontally between organisms. Although the impact of horizontal transfer (HT) of TEs is well recognized in prokaryotes, the frequency of this phenomenon and its contribution to genome evolution in eukaryotes remain poorly appreciated. Here, we provide evidence that a DNA transposon called SPIN has colonized the genome of 17 species of reptiles representing nearly every major lineage of squamates, including 14 families of lizards, snakes, and amphisbaenians. Slot blot analyses indicate that SPIN has amplified to high copy numbers in most of these species, ranging from 2,000-28,000 copies per haploid genome. In contrast, we could not detect the presence of SPIN in any of the turtles (seven species from seven families) and crocodiles (four species) examined. Genetic distances between SPIN sequences from species belonging to different squamate families are consistently very low (average = 0.1), considering the deep evolutionary divergence of the families investigated (most are >100 My diverged). Furthermore, these distances fall below interfamilial distances calculated for two genes known to have evolved under strong functional constraint in vertebrates (RAG1, average = 0.24 and C-mos, average = 0.27). These data, combined with phylogenetic analyses, indicate that the widespread distribution of SPIN among squamates is the result of at least 13 independent events of HTs. Molecular dating and paleobiogeographical data suggest that these transfers took place during the last 50 My on at least three different continents (North America, South America and, Africa). Together, these results triple the number of known SPIN transfer events among tetrapods, provide evidence for a previously hypothesized transoceanic movement of SPIN transposons during the Cenozoic, and further underscore the role of HT in the evolution of vertebrate genomes.

Diversidad alfa y beta de la comunidad de reptiles en el complejo cenagoso de Zapatosa, Colombia

Alfa and beta diversity of reptilian assemblages in Zapatosa wetland complex, Colombia. Diversity is a property of community that can described, characterized, and understood according to the functioning of ecosystems. To study the richness and local abundance and species replacement between habitats around the Zapatosa’s wetland complex (El Cesar Department), I carried out four field trips between November of 2006 and October of 2007. A total of 640 sampling hours/man analyzed five habitat types chasmophyte forest, dry forest, riparian forest, palm-grove and tree-lined savanna; with the exception of the palm-grove sampled at its 75%, the others were sampled up to their 80%. I found 847 reptiles that were distributed in 48 species. The group with the highest number of species was Colubridae with 14, followed by Gekkonidae with five. Five endemic species and eight with some conservation threat grade at a national level a re reported. The riparian forest was the richest and most abundant habitat with 34 species and 196 individuals. For each habitat, Colubridae had the highest number of species, followed by the families Polychrotidae, Gekkonidae and Teiidae, in that order. The reptile species composition was not different between the tree-lined savanna and the chasmophyte forest, but differed among the tree-lined savanna and the riparian forest, palm-grove and dry forest habitats. The most important differences in the species composition among almost all the habitats were influenced by the species Anolis tropidogaster and Gonatodes albogularis, and the higher occurrence of Stenocercus erythrogaster in the chasmophyte forest. The species replacement had an average value of 50%; the biggest amounts of shared species were the lizards, while the snake Leptodeira septentrionalis was the only one present in all habitat types. The forest grows-among-rocks showed the biggest complementarity and number of unique species compared to the other ...

La diversidad es una propiedad de las comunidades, permite describir, caracterizar y entender el funcionamiento de los ecosistemas. Para estudiar la riqueza, abundancia y el recambio de especies de reptiles entre hábitats circundantes al complejo cenagoso de Zapatosa, se realizaron cuatro salidas de campo (noviembre de 2006 y octubre de 2007). Se invirtieron 640h/hombre de muestreo repartido en cinco tipos de hábitat: bosque casmófito, bosque seco, bosque de ribera, palmar y sabana arbolada. Se encontraron 847 individuos de 48 especies, la familia más rica fue Colubridae, se registraron cinco especies endémicas y ocho con algún grado de amenaza en conservación a nivel nacional. El hábitat más diverso fue el bosque de ribera. La representatividad del muestreo en total y para cada hábitat fue superior al 80%, con excepción del palmar (<75%). La composición de especies fue diferente entre la sabana arbolada y los hábitats bosque de ribera, palmar y bosque seco. El recambio promedio de especies fue del 50%. El bosque casmófito mostró la mayor complementariedad y número de especies únicas. El complejo cenagoso presentó 2/3 de los reptiles registrados hasta hoy para la región Caribe y más del 80% de los encontrados para el departamento del Cesar.

Long bone histology of sauropterygia from the lower Muschelkalk of the Germanic basin provides unexpected implications for phylogeny.

BACKGROUND: Sauropterygia is an abundant and successful group of Triassic marine reptiles. Phylogenetic relationships of Triassic Sauropterygia have always been unstable and recently questioned. Although specimens occur in high numbers, the main problems are rareness of diagnostic material from the Germanic Basin and uniformity of postcranial morphology of eosauropterygians. In the current paper, morphotypes of humeri along with their corresponding bone histologies for Lower to Middle Muschelkalk sauropterygians are described and interpreted for the first time in a phylogenetic context. METHODOLOGY/PRINCIPAL FINDINGS: Nothosaurus shows a typical plesiomorphic lamellar-zonal bone type, but varying growth patterns and the occurrence of a new humerus morphotype point to a higher taxonomic diversity than was known. In contrast to the enormous morphological variability of eosauropterygian humeri not assigned to Nothosaurus, their long bone histology is relatively uniform and can be divided into two histotypes. Unexpectedly, both of these histotypes reveal abundant fibrolamellar bone throughout the cortex. This pushes the origin of fibrolamellar bone in Sauropterygia back from the Cretaceous to the early Middle Triassic (early Anisian). Histotype A is assigned to Cymatosaurus, a basal member of the Pistosauroidea, which includes the plesiosaurs as derived members. Histotype B is related to the pachypleurosaur Anarosaurus. Contrary to these new finds, the stratigraphically younger pachypleurosaur Neusticosaurus shows the plesiomorphic lamellar-zonal bone type and an incomplete endochondral ossification, like Nothosaurus. CONCLUSIONS/SIGNIFICANCE: Histological results hypothetically discussed in a phylogenetical context have a large impact on the current phylogenetic hypothesis of Sauropterygia, leaving the pachypleurosaurs polyphyletic. On the basis of histological data, Neusticosaurus would be related to Nothosaurus, whereas Anarosaurus would follow the pistosaur clade. Furthermore, the presence of fibrolamellar bone, which is accompanied with increased growth rates and presumably even with increased metabolic rates, already in Anarosaurus and Cymatosaurus can explain the success of the Pistosauroidea, the only sauropterygian group to survive into the Jurassic and give rise to the pelagic plesiosaur radiation.

Herpetofauna da Estação Ambiental de Peti, um fragmento de Mata Atlântica do estado de Minas Gerais, sudeste do Brasil / Herpetofauna of Estação Ambiental de Peti, an Atlantic Rainforest fragment of Minas Gerais State, southeastern Brazil

Here we provide a list of amphibians and reptiles of Estação de Pesquisa e Desenvolvimento Ambiental de Peti, an Atlantic rainforest reserve located in the mountains of the Espinhaço Range, State of Minas Gerais, southeastern Brazil. This list originated from a 78-days inventory conducted in the area 13 years after a first inventory. We actively searched for amphibians and reptiles in forest trails and anuran breeding sites. Between April 2002 and October 2004 we recorded 48 species belonging to Anura (29 species), Gymnophiona (1), Chelonia (1), Crocodylia (1), and Squamata (16 species: one amphisbaenian, five lizards and 10 snakes). Thirteen species were not recorded in the first inventory, and 14 species previously recorded were not found in the present work. Possible explanations for these differences are discussed. Although none of the recorded species is included in the available lists of threatened species for the State of Minas Gerais and Brazil, the reserve must be considered an important source of natural habitats to the local herpetofauna.

Fornecemos aqui uma lista de espécies de anfíbios e répteis da Estação de Pesquisa e Desenvolvimento Ambiental de Peti, uma reserva de Mata Atlântica localizada nas montanhas da Cadeia do Espinhaço, estado de Minas Gerais, sudeste do Brasil. Essa lista originou-se de um inventário conduzido durante 78 dias de trabalhos de campo, 13 anos após a realização de um primeiro levantamento. Entre abril de 2002 e outubro de 2004, aplicamos o método de procura visual durante caminhadas nas trilhas da floresta, em diversos corpos d'água e nos sítios reprodutivos dos anuros. Foram registradas 48 espécies, incluídas nas ordens Anura (29), Gymnophiona (1), Chelonia (1), Crocodylia (1) e Squamata (16 espécies: uma anfisbena, cinco lagartos e 11 serpentes). Treze espécies não haviam sido registradas no inventário anterior, e 14 espécies registradas anteriormente não foram detectadas em nosso inventário. São discutidas possíveis explicações para as diferenças observadas. Embora nenhuma espécie esteja incluída nas listas de espécies ameaçadas do Estado de Minas Gerais e do Brasil, a reserva deve ser considerada importante para a manutenção das populações da herpetofauna local.

Herpetofauna dos remanescentes de Mata Atlântica da região de Tapiraí e Piedade, SP, sudeste do Brasil / Herpetofauna of the Atlantic Forest remnants of Tapiraí and Piedade region, São Paulo state, southeastern Brazil

We present the species list of amphibians and reptiles registered in continuous and fragmented Atlantic Forest remnants at Tapiraí and Piedade municipalities, Atlantic Plateau of São Paulo, Brazil. We sampled 21 localities, 15 located within unprotetcted forest fragments and six located at Parque Estadual do Jurupará, the single legal protected area in this region and surroundings. We recorded 47 anurans, one gymnophiona, seven lizards, one amphisbenian, 46 snakes, and one turtle. The specimes were captured by pitfall traps with drift fences, visual and auditive surveys, incidental encounters, local collectors, and, for snakes, by recording scientific collection records. Sampling methods were effective in documenting local herpetofauna, showing the adequacy of the use of complementary methods. Forest remnants at Tapiraí and Piedade have typical species of Atlantic Forest areas, and show higher species richness in comparison with other lists in the Atlantic Plateau. The presence of species known from few localities, or present in threatened species lists, shows that the Atlantic Forest remnants in this region need conservation attention. Although still harboring high herpetofaunal diversity, the remnants are threatened by the effects of forest fragmentation.

Apresentamos aqui a lista de espécies de anfíbios e répteis registradas nos remanescentes de Mata Atlântica contínua e fragmentada da região de Tapiraí e Piedade, Planalto Atlântico de São Paulo, sudeste do Brasil. Amostramos 21 localidades na região, sendo 15 fragmentos florestais e seis localidades do interior e entorno do Parque Estadual do Jurupará, único remanescente legalmente protegido da região. Registramos 47 espécies de anfíbios anuros, uma espécie de gymnophiona, oito espécies de lagartos, uma espécie de anfisbena, 46 espécies de serpentes e uma espécie de quelônio. Esta lista conta com espécimes capturados pelos métodos de armadilhas de interceptação e queda, procura visual e auditiva, encontros ocasionais, capturas por terceiros e, no caso das serpentes, também por registros em coleção científica. A combinação entre métodos foi eficiente na amostragem da herpetofauna da região, evidenciando a necessidade de amostragem com métodos complementares. Os remanescentes de Tapiraí e Piedade apresentam espécies de anfíbios e répteis típicas de áreas de Mata Atlântica e alta riqueza de espécies, em relação a outros estudos realizados no planalto. A presença de espécies de distribuição restrita, ou presentes em listas de fauna ameaçada, reforçam a necessidade de conservação dos remanescentes de Mata Atlântica na região, que apesar de abrigar grande diversidade está ameaçada pelos efeitos da fragmentação florestal.

Identification of reptilian genes encoding hair keratin-like proteins suggests a new scenario for the evolutionary origin of hair.

The appearance of hair is one of the main evolutionary innovations in the amniote lineage leading to mammals. The main components of mammalian hair are cysteine-rich type I and type II keratins, also known as hard alpha-keratins or "hair keratins." To determine the evolutionary history of these important structural proteins, we compared the genomic loci of the human hair keratin genes with the homologous loci of the chicken and of the green anole lizard Anolis carolinenis. The genome of the chicken contained one type II hair keratin-like gene, and the lizard genome contained two type I and four type II hair keratin-like genes. Orthology of the latter genes and mammalian hair keratins was supported by gene locus synteny, conserved exon-intron organization, and amino acid sequence similarity of the encoded proteins. The lizard hair keratin-like genes were expressed most strongly in the digits, indicating a role in claw formation. In addition, we identified a novel group of reptilian cysteine-rich type I keratins that lack homologues in mammals. Our data show that cysteine-rich alpha-keratins are not restricted to mammals and suggest that the evolution of mammalian hair involved the co-option of pre-existing structural proteins.