The early part of the Ordovician Period witnessed the rapid radiation of many of the invertebrate groups that rose to dominate the world's Paleozoic oceans. The echinoderms of this age, however, are poorly known, throwing into controversy the relationships between Cambrian and later Ordovician representatives of the phylum. Dr. James Sprinkle proposes to collect and study three newly discovered local faunas of early Ordovician echinoderms from the Rocky Mountain region. This research project will provide the basis for determining the evolutionary rates active within the group during this critical interval. In particular, better data for the earliest Ordovician would establish whether the Paleozoic radiation proceeded in two phases of evolutionary diversification disjoined by an extinction episode, or whether a single protracted growth of diversity occurred but is poorly preserved and sampled. The proposed research will address an important gap in our knowledge of a major taxonomic group during a critical episode of earth history. The results of the project will contribute to a controversy that has a wide audience.
