A total evidence assessment of the phylogeny of North American euctenizine trapdoor spiders (Araneae, Mygalomorphae, Cyrtaucheniidae) using Bayesian inference.

North American trapdoor spiders of the subfamily Euctenizinae (Cyrtaucheniidae) are among the most diverse mygalomorph spiders (trapdoor spiders, tarantulas, and their relatives) on the continent in terms of species numbers and ecological habits. We present a generic level phylogenetic study of the subfamily based on a total evidence approach. Our dataset comprises approximately 3.7 kb of molecular characters (18S and 28S rRNA gene sequences) and 71 morphological characters scored for 32 taxa. When analyzed independently, these data sets, particularly the morphology, depict very different views of mygalomorph and euctenizine relationships, albeit with weak support. However, when these data are combined we recover a tree topology that is supported by high posterior probability for most nodes. The combined data recover a phylogenetic pattern for euctenizines different than previously published and indicate the presence of a narrowly endemic new genus from central California. While euctenizine monophyly is unequivocal, the monophyly of a number of other mygalomorph groups is questionable (e.g., Cyrtaucheniidae, Mecicobothriodina, Rastelloidina). This non-monophyly is noteworthy, as our analysis represents the first employing a total evidence approach for mygalomorphs, a group known to be morphologically conservative.