Phylogeny of the spider genus I xchela H uber, 2000 ( A raneae: P holcidae) based on morphological and molecular evidence ( CO1 and 16S ), with a hypothesized diversification in the P leistocene

The genus I xchela   H uber is composed of 20 species distributed from n orth‐eastern M exico to C entral A merica, including the five new species described here from M exico: Ixchela azteca sp. nov. , Ixchela jalisco sp. nov. , Ixchela mendozai sp. nov. , Ixchela purepecha sp. nov. and Ixchela tlayuda sp. nov. We test the monophyly and investigate the phylogenetic relationships among species of the genus I xchela using morphological and molecular data. Parsimony ( PA ) analysis of 24 taxa and 40 morphological characters with equal and implied weights supported the monophyly of I xchela with eight morphological synapomorphies. The PA analyses with equal and implied weights, and separate B ayesian inference ( BI ) analyses for the CO1 gene (506 characters), concatenated gene fragments CO1  +  16S (885 characters), morphology +  CO1 (546 characters) and the combined evidence data set (morphology +  CO1  +  16S ) (925 characters) support the monophyly of I xchela . Our preferred topology shows two large clades; clade 1 has a natural distribution in the M esoamerican biotic component, whereas clade 2 predominates in the M exican M ontane biotic component. The genus I xchela diverged in the late M iocene, and the divergence between the internal clades in the genus occurred in the late P liocene; by contrast, most of the speciation events seem to have occurred mainly during the Pleistocene, where climatic changes brought on by repeated glaciations played an important role in the diversification of the genus. © 2015 The Linnean Society of London