Federico Arias

Speciation with gene flow in whiptail lizards from a Neotropical xeric biome

Two main hypotheses have been proposed to explain the diversification of the Caatinga biota. The riverine barrier hypothesis (RBH) claims that the São Francisco River (SFR) is a major biogeographic barrier to gene flow. The Pleistocene climatic fluctuation hypothesis (PCH) states that gene flow, geographic genetic structure and demographic signatures on endemic Caatinga taxa were influenced by Quaternary climate fluctuation cycles. Herein, we analyse genetic diversity and structure, phylogeographic history, and diversification of a widespread Caatinga lizard (Cnemidophorus ocellifer) based on large geographical sampling for multiple loci to test the predictions derived from the RBH and PCH. We inferred two well‐delimited lineages (Northeast and Southwest) that have diverged along the Cerrado–Caatinga border during the Mid‐Late Miocene (6–14 Ma) despite the presence of gene flow. We reject both major hypotheses proposed to explain diversification in the Caatinga. Surprisingly, our results revealed a striking complex diversification pattern where the Northeast lineage originated as a founder effect from a few individuals located along the edge of the Southwest lineage that eventually expanded throughout the Caatinga. The Southwest lineage is more diverse, older and associated with the Cerrado–Caatinga boundaries. Finally, we suggest that C. ocellifer from the Caatinga is composed of two distinct species. Our data support speciation in the presence of gene flow and highlight the role of environmental gradients in the diversification process.

A New Species of Ameivula (Squamata, Teiidae) from Southern Espinhaço Mountain Range, Brazil

In a recent phylogenetic analysis of Teiidae based on morphological characters, three new genera were erected to remove polyphyletism in the genus Cnemidophorus. Accordingly, Ameivula was proposed to accommodate the species formerly included in the Cnemidophorus ocellifer group, characterized by the presence of granules in the supraocular semicircles, femoral pores fewer than 40, and preanal spurs absent. Here we describe a new species of Ameivula from the mountain region of Parque Nacional Serra do Cipó, Minas Gerais, that is apparently endemic to high elevations between 900 and about 1200 m. The new species can be easily distinguished from its congeners by the presence of three supraocular scales, a contact between frontoparietal scale and the third supraoculars (circumorbital with an incomplete series of granules), a third pair of chinshields larger than the others and low number of fourth finger lamellae. En un reciente análisis filogenético de Teiidae, basado en caracteres morfológicos tres nuevos géneros fueron propuestos para eliminar el polifiletismo de Cnemidophorus. En consecuencia, Ameivula fue propuesto para acomodar a las especies antiguamente incluidas en el grupo de Cnemidophorus ocellifer, caracterizado por la presencia de semicírculos supraoculares, un bajo número de poros femorales y ausencia de espinas en la base de la cloaca. Aquí describimos una nueva de este género de la región montañosa del Parque Nacional Serra do Cipó, estado de Minas Gerais, aparentemente endémica de elevaciones comprendidas entre 900 m y 1200 m. La nueva especie puede ser fácilmente distinguible de sus cogenéricas por tener tres escamas supraoculares, escama frontoparietal en contacto con la tercera supraocular (semicírculo de gránulos incompletos), tercero par de geneiales más grande que los demás y un número bajo de lamellas del cuarto dedo de la mano.

Range extension and geographic distribution of the poorly known species, Contomastix leachei Peracca, 1897 (Squamata: Teiidae)

The records of distribution of Contomastix leachei Peracca, 1897 indicate that this species is endemic of Southeast Jujuy Province, occurring only in the Ledesma Department. Here, we report the southernmost known locality of this species, from Alemania, Salta Province, Argentina. This record represents the southern limit of distribution of the species. We also provide an updated range map for this species based on data from museum records and field studies.

Diversity of teiid lizards from Gran Chaco and Western Cerrado (Squamata: Teiidae)

The Gran Chaco dry forest ecoregion corresponds to the southern portion of the South America diagonal belt of open formations, being one of the most threatened subtropical woodland savannas in the world. The area is still poorly known biologically and has been suffering with impressively high forest cover loss in the last 10 years. Integrating morphological and molecular data, we detected and describe a cryptic new species of lizard genus Ameivula endemic from the eastern part of this ecoregion, the called Humid Chaco. Ameivula apipensis sp nov. is characterised by a whitish brown vertebral stripe in adults and juveniles, a lateral field without ocelli and with overlapping spot, presence of an interfrontoparietal scale in 46.2% of the specimens, 12–17 femoral pores, an hemipenis without lateral sac, five xiphisternal ribs, and by a combination of meristic features as confirmed by discriminant analysis. The new species was recovered sister to a clade from Western Cerrado in our analysis, the first phylogenetic hypothesis for the Ameivula and Glaucomastix genera based on 1977 base pairs of three mitochondrial (12S, 16S and cyt‐b) and one nuclear (c‐mos) genes, including all the recognised species at the moment. Maximum parsimony and Bayesian inference recovered the monophyly of Ameivula and Glaucomastix with strong support. Reinforcing previous studies, our results suggest the presence of additional cryptic species in Ameivula from the Western Cerrado.

Align_NE.SW_R35_268.phased.sequeces

This file contains R35 aligned sequences used in most phylogeographic analyses: population assignment, haplotype genealogy, species tree estimation, migration estimate, species validation, and model based approach. Northeast (NE) sequences cluster was used separately in phylogeographic reconstruction.

Contomastix serrana (Cei & Martori, 1991). Primer registro para la provincia del Chaco (República Argentina)

Se da a conocer el hallazgo de Contomastix serrana para el Parque Natural Provincial Fuerte Esperanza, siendo este el primer registro para la provincia del Chaco, extendiendose 60 km al norte la distribucion de esta especie.