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| Author(s): |
Julia Klaczko
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2007-02-15 |
| Examining board members: |
Hussam El Dine Zaher;
Francisco Luís Franco;
Paulo Christiano de Anchietta Garcia;
Sergio Russo Matioli;
Miguel Trefaut Urbano Rodrigues
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| Advisor: | Hussam El Dine Zaher |
| Abstract | |
Chironius, one of the greatest genera of the Colubrinae subfamily in South America, consists of 14 species, diagnosed by the presence of 10 or 12 rows of dorsal scales in the mid-body. The genus presents a Neotropical distribution extending from the northern coast of Honduras to Uruguay and northeastern Argentina. This study presents a combined phylogenetic analysis of 75 morphological characters and 1397 molecular characters (from the sequences of two mitochondrial genes, 12S and 16S, as well as a nuclear gene, c-mos) by means of Maximum Parsimony and Bayesian Inference. The monophylety of the genus Chironius was corroborated and the obtained results suggest that the genus is subdivided in ten monophyletic components. The genera Drymobius, Leptophis and Dendrophidion come out as the most closely related to Chironius, corroborating previous studies. Chironius laevicollis and C. scurrulus composed the most basal clade among the species. Their distribution is restricted to South America, which suggests that Chironius originated in South America and later invaded Central America through dispersion. (AU) | |