 Such professors include Carl Owen Dunbar (the Director of the Peabody Museum at Yale University, 1942–1959), Richard Swann Lull, G. Edward Lewis, and George Wieland.It features a timeline of 350 million years of animal and plant evolution, showing the rise and fall of dinosaurs as the rulers of Earth.Zallinger used trees to divide it into the various periods of geologic time, as the chronology moves from right to left.