Taxonomic revision of the tribe Dipsadini (Serpentes: Dipsadidae, Dipsadinae)

Author(s)

Paola María Sánchez Martínez

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2016-09-02

Examining board members

Hussam El Dine Zaher; Francisco Luís Franco; Giovanna Gondim Montingelli; Paulo Gustavo Homem Passos; Ana Lúcia da Costa Prudente; Miguel Trefaut Urbano Rodrigues

• Advisor: Hussam El Dine Zaher

Abstract

The tribe Dipsadini, a group of neotropical snail-eating snakes, includes 71 recognized species, belonging to the genera Dipsas, Plesiodipsas, Sibon, Sibynomorphus and Tropidodipsas, distributed from Mexico to northern Argentina. The genera of this tribe feature an extensive variation of color patterns and scale counts; characters that are the basis of this systematic group. Although taxonomic studies of some species and groups of species within the tribe have been published recently the taxonomy presented has been unstable. This is due to the use of morphological characters that have several intermediate forms between the described species that in turn are not clear. This review included a sample of about 1600 specimens covering the most of the species of the tribe and its geographical distribution. The taxonomic analysis of fifty of these species was carried out using color pattern, hemipenial morphology together with meristic and morphometric characters. The list of synonyms of all species of the tribe was checked to clarify the current taxonomic status of each, which allowed for an improved taxonomic definition of the tribe. In this taxonomic revision 66 valid species were recognized, a lectotype was designated, six species were synonymized, five species have been revalidated, and four species were excluded from the tribe, justifying the need for the two new genus descriptions to place them. Likewise, the description of a new genus is recommended to place the species of Sibynomorphus with Andean distribution. The formal status of several species of the tribe is not clear and these have been treated indistinctly as valid species or synonyms, by different authors. Therefore, the formal clarification of the taxonomic status of these species is necessary prior to any changes being made, in the interests of nomenclatural stability (AU)

• FAPESP's process: 12/11997-3 - Taxonomic revision of the tribe Dipsadini (Serpentes: Dipsadidae: Dipsadinae)
• Grantee: Paola María Sánchez Martínez
• Support Opportunities: Scholarships in Brazil - Doctorate