A new species of hognose pitviper, genus Porthidium, from the southwestern Pacific of Costa Rica (Serpentes: Viperidae)

A new species of terrestrial pitviper, Porthidium porrasi, is described from mesophytic forests of the Península de Osa and surrounding area of the Pacific versant of southwestern Costa Rica. It is most similar to P. nasutum and is characterized by a pattern of bands, persistence of the juvenile tail color in adults, and a high number of dorsal scales. Analysis of mtDNA sequences confirms its distinction from P. nasutum. The existence of this species reinforces the notion of elevated herpetofaunal endemism in southwestern Costa Rica.

A new species of slender coralsnake from Colombia, and its clinal an ontogenetic variation (Serpentes, Elapidae: Leptomicrurus)

Leptomicrurus renjifoi is described from tropical semi-deciduous forest of the eastern Colombian Ilanos. It is one of the smallest species in the genus, is most similar to L. scutiventris, and it may be distinguished from known congeners by a combination of color, pattern, and scale characters. Evidence for the recognition of Leptomicrurus is convincing, although its members were recently thought to comprise a closely related assemblage within Micrurus. A supposedly aberrant specimen of L. scutiventris may indicate clinal or ontogenetic variation in pattern.

A taxonomic reevaluation of Phrynops (Testudines: Chelidae) with the description of two new genera and a new species of Batrachemys

Relationships among turtle species loosely categorized within the South American genus Phrynops are explored. Three once recognized genera (Batrachemys, Mesoclemmys and Phrynops) that were demoted to subgenera, and then synonymized with Phrynops, are demonstrated to warrant full recognition based on morphometric analysis, skull osteology, and mitochondrial and nuclear gene sequencing. Mesoclemmys is resurrected from the synonymy of Phrynops as a monotypic genus including M. gibba. The genus Rhinemys, previously a synonym of Phrynops, is resurrected for the species R. rufipes. Ranacephala gen. nov. is described to include the species R. hogei. The genus Batrachemys is resurrected from the synonymy of Phrynops and includes B. dahli, B. nasuta, B. raniceps, B. tuberculata, and B. zuliae. The taxon vanderhaegei is placed in Bufocephala gen. nov. The genus Phrynops is redefined to include the taxa P. geoffroanus, P. hilarii, P. tuberosus, and P. williamsi. Cladistic analysis of morphological data supports this taxonomy. A new species of Batrachemys is described from the western Amazon region, and is distinguished by having facial markings in juveniles, a relatively wide head, and a flattened shell. The new species, B. heliostemma sp. nov., is sympatric with and most similar to the recently resurrected form Batrachemys raniceps in the upper Amazonian region of Peru and adjacent Brazil, Ecuador, Venezuela, and Colombia. Lastly, morphometric data from living and museum specimens of all species of Batrachemys are presented.