Meeting Abstract

94.3  Friday, Jan. 7  Seeing stars: A molecular and morphological investigation of the evolutionary history of the Odontasteridae (Asteroidea: Echinodermata) JANOSIK, A.M.*; HALANYCH, K.M.; Auburn University; Auburn University janosam@auburn.edu

Odontasterids (Asteroidea: Echinodermata) comprise a clade described by A.E. Verrill in 1899 and are placed within Valvatida, a derived assemblage of sea stars. Boasting a worldwide distribution, Odontasterids are found in the Southern, Atlantic, and Pacific Oceans, with a concentration in cold-water habitats, in high latitudes in the Southern Hemisphere. Most of species of Odontasteridae are from the lower shelf and upper bathyal region, though some have been collected in the tidal zone, which is similar to the common asteroid ancestry of the invasion of shallow waters from deeper waters. Odontasteridae includes the following genera: Acodontaster, Diabocilla, Diplodontias, Eurygonias, Hoplaster, and Odontaster, which are typically characterized by two series of equal, opposite and usually conspicuous marginal plates without intermarginal channels. They also usually possess triangular mouths and two rows of tubefeet with suckers. This group of organisms occupies an important role in both planktonic and benthic marine environments and is important to the understanding of marine systems. To date, the phylogenetic and evolutionary history within the Odontasteridae has not been rigorously examined. We present a comprehensively sampled molecular and morphological phylogenetic analysis of of the Odontasteridae to assess interrelationships among and between genera. Biogeographic and distributional patterns of species are discussed. Generally, our results indicate that species present in high latitudes in the Southern Hemisphere (i.e. Southern Ocean) are the most derived clades.