81.4 Sunday, Jan. 6 A Global Phylogeny of Freshwater Crayfishes with Divergence Time Estimates CRANDALL, Keith A.*; BUHAY, Jennifer E.; BREINHOLDT, Jesse; RALSTON, Nathaniel; SEAMONS, Ryan; Brigham Young University; University of South Carolina; Brigham Young University; Brigham Young University; Brigham Young University email@example.com
Freshwater crayfish form a monophyletic group sister to clawed lobsters, and represent approximately 640 described species. These species are distributed on all continents except Antarctica with centers of diversity in the southeast United States and in Victoria, Australia. Taxonomically, the freshwater crayfish are grouped into two monophyletic superfamilies representing the Northern Hemisphere Astacoidea and the southern hemisphere Parastacoidea. While there is ample evidence for the monophyly of the freshwater crayfish as well as for these two groups, we present evidence that the lower taxonomic designations do not reflect evolutionary history as estimated through multi-gene sequence analysis and associated phylogenetic reconstruction. With an extensive molecular data set, we present a global phylogeny of the freshwater crayfish and suggest potential taxonomic revisions associated with the major divergences. Furthermore, we estimate the timing of the major divergences using relaxed molecular clock approaches and compare these divergences to the broader decapod diversification events.