Meeting Abstract
The grass spider subfamily Ageleninae (Araneae: Agelenidae) is distributed throughout North America. However, in the western part of the distribution, they are incredibly species rich with 129 species in 10 genera endemic to the region. However, other North American agelenine taxa with widespread and Gulf/Caribbean distributions (3 genera, 28 species) are clearly diverged morphologically from the Western taxa, based on spinneret shape and male genitalia. The affinities of the North American taxa with worldwide Agelenidae, particularly the Eurasian taxa, have been difficult to decipher. Here we attempt to test both the monophyly of the North American taxa and their relationships to worldwide taxa. To answer these two questions we analyzed genetic data from targeted genes using Bayesian likelihood to construct a phylogenetic hypothesis. A monophyletic relationship between the western and eastern North American groups was not recovered, and the eastern North American group is more closely related to the Eurasian taxa. Additional analyses using molecular clock estimates for the age of the subfamily (~50 MY) disallow an obvious vicariant event induced from the opening of the Atlantic at 66 MYA, leaving trans-oceanic dispersal as a potential cause for the surprising sister relationship.
