New Taxa and Cryptic Species of Neotropical Snakes (Xenodontinae), with Commentary on Hemipenes as Generic and Specific Characters

A new rare species of the Rhadinaea decorata group from the Sierra Madre del Sur of Guerrero, Mexico (Squamata, Colubridae)

“…We followed Pesantes (1994), Myers and Cadle (2003), Zaher and Prudente (2003), and Angarita-Sierra (2014) for hemipenial preparation. We follow Zaher (1999) and Myers and McDowell (2014) for hemipenial morphological terminology.…”

First records in Brazil for Arthrosaura versteegii van Lidth de Jeude, 1904 (Reptilia, Gymnophthalmidae), a possible species complex, and distribution extension for Arthrosaura montigena Myers & Donnelly, 2008, in Venezuela

“…In the case of the specimens studied here, it is interesting to note that the largest differences were not found between the population north of the Amazon and those south of it, but between the 2 populations in Pará, both in the Xingu-Tapajós interfluve. Irrespective of whether they represent the same or distinct species, considering that the hemipenis of the specimens from Novo Progresso differs from those of most Arthrosaura species, we may suppose that this population may have undergone some strong selective pressure that led to hemipenial divergence, as proposed in other cases by Myers and McDowell (2014). However, without additional studies to give a better picture of the variation in the whole group and how these populations relate to each other, any conclusion would be too speculative.…”

“…Intraspecific variation in hemipenis has already been observed in lizards and snakes. Myers and McDowell (2014) discuss several cases of hemipenial polymorphism, especially in snakes, demonstrating that it is not possible to assume any explanation a priori as granted. Despite frequently being considered conservative, in some cases hemipenes seem to evolve rapidly, showing large differences within a species or in closely related species.…”

A large and unusually colored new snake species of the genusTantilla(Squamata; Colubridae) from the Peruvian Andes

“…Data on morphological traits of other South American colubrid species and genera were taken from Peracca (1904), Van Denburgh (1912), Werner (1924), Stuart & Bailey (1941), Slevin (1942), Smith & Taylor (1945), Stuart (1949), Stuart (1954), Peters (1960), Fritts & Smith (1969), Peters, Donoso-Barros & Orejas-Miranda (1970), Villa (1971), Villa (1990), Myers (1973), Wilson (1976), Wilson (1987), Wilson (1999), Wilson & Mena (1980), Savage & Donnelly, 1988, Pérez-Santos & Moreno, 1988, Savage & Crother (1989), McCranie & Wilson (1991a), McCranie & Wilson (1991b), McCranie & Wilson (1992), McCranie & Villa (1993), Cei (1993), Ferrarezzi (1993), Puorto & Ferrarezzi, 1993, Myers & Cadle (1994), Smith & Campbell (1994), Campbell, Camarillo & Ustach (1995), Zaher (1996), Zaher (1999), Franco, Marques & Puorto (1997), Campbell (1998), Campbell & Smith (1998), Starace (1998), Kornacker (1999), Savage (2002), Sawaya & Sazima (2003), Köhler (2003), Köhler (2008), McCranie & Castaneda (2004), Solorzano, 2004, Stafford (2004), Lema, D’Agostini & Cappelari (2005), Scott et al (2006), Cacciali, Carreira & Scott (2007), Harvey et al (2008), Jansen & Köhler (2008), Zaher et al (2009), Myers (2011), Passos, Ramos & Pereira (2012), Moura Ribeiro, Caldeira Costa & Magalhães Pirani (2013), Townsend et al (2013) Myers & McDowell (2014), Wilson & Mata-Silva (2015) and Wilson & Mata-Silva (2014).…”