Evolutionary analysis of Chironius snakes unveils cryptic diversity and provides clues to diversification in the Neotropics.

Recent hypotheses to explain tropical diversity involves the Neogene and Quaternary geoclimatic dynamics, but the absence of unambiguous data permitting the choice between alternative hypotheses makes a general theory for the origin of tropical biodiversity far to be achieved. The occurrence of Chironius snakes in well-defined biogeographical regions led us to adopt Chironius as a model to unveil patterns of vertebrate diversification in the Neotropics. Here, we used molecular markers and records on geographic distribution to investigate Chironius evolution and, subsequently, providing hints on diversification in the Neotropics.

Snake richness in urban forest fragments from Niterói and surroundings, state of Rio de Janeiro, southeastern Brazil.

Background: The Atlantic Forest is a hotspot for biodiversity, an area which houses high species richness and endemism, but with high level of threat. With reference to the herpetofauna, until recently there has been no detailed information regarding diversity of snakes recorded in the Atlantic Forest, the number of endemic species and their distribution ranges. While these basic data were missing, large areas of original forest have continued to be lost to increased urbanization and human population, representing a severe threat to the biodiversity.

Taxonomic revision of Chironius flavolineatus (Jan, 1863) with description of a new species (Serpentes: Colubridae).

We conducted a taxonomic review of Chironius flavolineatus on the basis of continuous and discrete morphological characters. We recognize a new species which is distinguished from all currently recognized congeners by the following unique combination of characters: first third of body black or dark gray; vertebral stripe yellowish or creamish white distinct from dorsals of nape and extending throughout almost whole body length; head dorsum tan to brown, distinct from background color of first third of body; posterior temporal scales ranging one to four; cloacal shield frequently divided; two to four rows of keeled dorsal scales at midbody; venter ground color gradually darkening towards cloaca; region of medial constriction of hemipenis slightly covered with spinules separating calyces of apex from spines below region of constriction; in lateral view, sulcus spermaticus positioned on convex face of hemipenis; ascending process of premaxilla oblique anteroposteriorly to longitudinal axis of skull; optic fenestrae not exceeding frontoparietal suture; posterior border of supratemporal exceeding braincase; dorsoventral axis of quadrate oblique mesolaterally, moving away from longitudinal axis of skull. Furthermore, we provide data on morphological variation, distribution, and an emended diagnosis for C.

A new species of Chironius Fitzinger, 1826 from the state of Bahia, Northeastern Brazil (Serpentes: Colubridae).

We describe a new species of Chironius Fitzinger, 1826 from the highlands of Chapada Diamantina, state of Bahia, Brazil. The new species is distinguished from all currently recognized congeners by a unique combination of states of characters on coloration, scale counts, scale ornamentation, and hemipenis. The new species closely resembles Chironius flavolineatus (Jan, 1863) in color pattern, but differs from the later taxon by the presence of two to four posterior temporal scales; cloacal shield entire; six to ten rows of keeled dorsal scales at midbody; ventral scales with posterior dark edges forming conspicuous transverse bars along almost the entire venter; conspicuous dark longitudinal stripes (in "zigzag") in the midventral portion of subcaudals; region of medial constriction of hemipenis slightly covered with spinules separating calyces of apex from spines below region of constriction; and sulcus spermaticus situated on convex face of hemipenis in lateral view.

On the identity of Chironius flavolineatus (Serpentes: Colubridae).

The snake genus Chironius Fitzinger, 1826 is endemic to the Neotropical region, occurring from Honduras to Uruguay and northeastern Argentina. Some species of the genus have taxonomic and/or nomenclatural problems, such as C. flavolineatus which lacks agreement in the literature about its authorship and type locality.

Redescription of Phalotris labiomaculatus (Serpentes, Dipsadidae, Elapomorphini), with notes on the taxonomic boundaries within the nasutus group.

Phalotris labiomaculatus Lema, 2002 was described based on a single specimen from Porto Franco, south of the Brazilian state of Maranhão, being rediscovered three years later in Mateiros, a municipality in the north of the state of Tocantins, attesting to its occurrence in the cerrado of both banks of the Tocantins River. The discovery of 28 new specimens from other localities during field expeditions (2009-2011) allowed a redescription of the species, adding new data on meristic and morpho-qualitative traits. These results enable a better diagnosis of intraspecific, ontogenetic and sexual variation, consolidating its taxonomic relationships with other species belonging to the nasutus group.