2016-12-23T18:52:10

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Comprehensive assessments of species’ extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4–7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened—confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods—agriculture, logging, urban development and invasive species—although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles—including most species of crocodiles and turtles—require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

We update the list of reptiles of Venezuela, reporting a total of 370 species from the country (four of these exotic), arrangedin 122 genera (one exotic), 30 families and three orders. Introduced species and dubious or erroneous records are discussed.Taxonomic, nomenclatural and distributional comments are provided when required. Considering species of probableoccurrence in the country (known to occur in Colombia, Brazil and Guyana at localities very close to the Venezuelan border) and still undescribed taxa, we estimate that the total number of species in Venezuela could exceed 400.Se actualiza la lista de reptiles de Venezuela a un total de 370 especies (cuatro de ellas exóticas), pertenecientes a 122géneros (un exótico), 30 familias y tres órdenes. Se discuten las especies introducidas, los registros dudosos o erróneos yse proporcionan comentarios taxonómicos, nomenclaturales o de distribución en casos necesarios. Después de considerarlas especies de probable presencia en el país (registros conocidos cercanos a la frontera con Colombia, Brasil y Guyana) y los taxones aun no descritos, se estima que el número total de especies en Venezuela podría superar las 400 especies.

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Riama is the most speciose genus of the Neotropical lizard family Gymnophthalmidae. Its more than 30 montane species occur throughout the northern Andes, the Cordillera de la Costa (CC) in Venezuela, and Trinidad. We present the most comprehensive phylogenetic analysis of Riama to date based on a total evidence (TE) approach and direct optimization of molecular and morphological evidence. Analyses use DNA sequences from four loci and 35 phenotypic characters. The dataset consists of 55 ingroup terminals representing 25 of the 30 currently recognized species of Riama plus five undescribed taxa, including an endemic species from the Sierra Nevada de Santa Marta (SNSM) in Colombia, and 66 outgroup terminals of 47 species. Analysis results in a well-supported hypothesis in which Riama is polyphyletic, with its species falling into three clades. The Tepuian Anadia mcdiarmidi nests within one clade of Riama, and the recently resurrected Pantodactylus nests within Cercosaura. Accordingly, we propose a monophyletic taxonomy that reflects historical relationships. Analysis of character evolution indicates that the presence/absence of prefrontals-a cornerstone of the early genus-level taxonomy of cercosaurines-is optimally explained as having been plesiomorphically present in the most recent common ancestor of Cercosaurinae and lost in that of the immediately less inclusive clade. Multiple independent reversals to present and subsequent returns to absent occur within this clade. To evaluate the impact of phenotypic evidence on our results, we compare our TE results with results obtained from analyses using only molecular data. Although phenotypic evidence comprises only 1.2% of the TE matrix, its inclusion alters both the topology and support values of the clades that do not differ. Finally, current phylogenetic evidence reveals a SNSM-CC-Trinidad-tepuis biogeographical link. We hypothesize that an ancient connection facilitated the exchange of species between the SNSM and the CC.

A new gymnophthalmid lizard of the genus Anadia Gray, 1845 is described from the summit of Abakapá-tepui, Bolívar state, Venezuela, between 2200-2242 m elevation. The new species, Anadia mcdiarmidi sp. nov., is endemic to the Chimantá Massif and seemingly also occurs on Amurí-tepui and Murei-tepui. The new taxon is mainly distinguished from all known congeners by the following combination of characters: body fairly robust, tail longer than SVL, dorsal scales small, quadrangular, middorsal scales 53-57, suboculars large, subequal in size, with sometimes one scale slightly protruding downward between 4^th and 5^th supralabial, nasal entire, without sub-nostril groove, body uniform greyish to bluish brown in life, devoid of any conspicuous pattern in males, venter immaculate golden grey in life, femoral pores not extending onto preanal area, 9-10 on each side in males, preanal pores absent, hemipenis globose, weakly bilobed, bordered by numerous flounces (>20) bearing comblike rows of minute weakly mineralized spinules.