MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
Phylogeny, species delimitation and convergence in the South American bothriurid scorpion genus Brachistosternus Pocock 1893: Integrating morphology, nuclear and mitochondrial DNA
MATTONI, C.I.; CECCARELLI, M.F.; OJANGUREN-AFFILASTRO, A. A.; RAMÍREZ, M.J.; OCHOA, J.A.; PRENDINI, L.
MOLECULAR PHYLOGENETICS AND EVOLUTION
ACADEMIC PRESS INC ELSEVIER SCIENCE
Lugar: Amsterdam; Año: 2016 vol. 94 p. 159 - 159
A phylogenetic analysis of the scorpion genus Brachistosternus Pocock (Bothriuridae) is presented. It is based on a dataset including 41 of the 43 described species of Brachistosternus plus four outgroups, scored for 116 morphological characters and five molecular markers. We included three fragments of mitochondrial DNA (12S; 16S and COI), and two fragments of nuclear DNA (18S and 28S), exceeding a total of 4200 bp. The phylogenetic analyses using parsimony, maximum likelihood and Bayesian analyses are largely congruent and show high support in most clades. Our results support the monophyly of the genus and the two subgenera, as obtained in earlier analyses, but have otherwise important differences. Species from plains in the Atacama Desert have split basally, whereas the high altitude Andean species have radiated from a more derived ancestor and diversified notably, presumably as a result of the rising of the Andes, and all the related climatic and geomorphologic process. The phylogenetic trees obtained with molecular data, together with a morphological dataset allowed the mapping of two syndromes of characters that together define the specialization to living on sand (psammophily) and the complexity of the male genital structures (the hemispermatophores). We detected four convergent transitions to psammophily, a sharp transition to complex hemispermatophores in Brachistosternus, followed by three further transitions to higher complexity and three independent transitions to simple structures. In species that present taxonomic problems as different morphs inside a species, or overlapping morphology between species, we tested species delimitation as well as co-specificity, both intra and inter-specific.