Morphology, phylogeny and taxonomy of Southamerican bothropoid pitvipers (Serpentes, Crotalinae).

CARRASCO PAOLA A.; MATTONI CAMILO; SCROCCHI GUSTAVO J.; LEYNAUD GERARDO C.

ZOOLOGICA SCRIPTA

WILEY-BLACKWELL PUBLISHING, INC

Año: 2012 vol. 41 p. 109 - 124

0300-3256

Southamerican bothropoids comprise a monophyletic and greatly diverse group of pitvipers that were earlier included in the genus Bothrops and further assigned to five genera. Up to the present, most phylogenetic analyses of bothropoids used mitochondrial DNA sequences while few of them included morphological traits. Moreover, the systematic affinities of some species remain unclear. Here we performed a parsimony analysis of morphological data based on the examination of 111 characters related to lepidosis, coloration, osteology and hemipenial morphology of 35 of the 47 species that conform the bothropoid group. The data contains new morphological information and include species that have been rarely treated in phylogenetic studies. The morphological data was analyzed separately and combined with 2398 molecular characters obtained from published sequences of four mitochondrial genes. Five characters of the ecology were also included. A sensitivity analysis was performed using different weighting criteria for the characters. The congruence between different sources of evidence was evaluated through partitioned and total evidence analyses, the analyses of reduced datasets, and the use of ILD test. With some exceptions, results showed similar groups of species than previous studies, but revealed incongruences between morphological and molecular characters, and within the molecular partition. This conflict affect the relationship between particular groups of species, leading to alternative phylogenetic hypotheses for bothropoids: hierarchichal radiation or two major lineages within the group. The results also showed Bothrops sensu stricto being paraphyletic. We discuss previous taxonomic approaches and, considering both hypotheses, we propose an arrangement that rectifies the paraphyly of Bothrops while attending taxonomic stability.