Paleoecology, paleobiography and systematic paleontology of Ordovician-Devonian brachiopods, conodonts, and molluscs (gastropods); high-resolution biostratigraphy using integrated brachiopod and conodont sequences for correlation; integrated sequence-event stratigraphy, chemostratigraphy and magnetostratigraphy of Devonian cratonic and continental platform deposits of North America; paleogeography of Devonian Luarussia and paleoceanography of the Devonian ocean.