After the dinosaurs vanished, Earth became a lush, tropical hothouse. Dense forests flourished, stabilizing soil and reshaping rivers . Giant creatures roamed—Titanoboa, a 45-foot snake, slithered through swamps, while penguins over six feet tall waddled along coasts . Mammals quickly evolved to fill empty roles, giving rise to primates, rodents, and hoofed animals . A quiet, warm world emerging from catastrophe, slowly building the foundation for everything we know today