Reconstruction of the Trans-Saharan Seaway waters (opposite page, foldout; with key above) from the Late Cretaceous–early Paleogene by Carl Buell. Sunlight of the tropics illuminated seawater fi lled with mangrove roots near shore where freshwater infl uence was highest. Mollusks lined the fl oor of the shallow sea, and tube-shaped burrows opened onto the seafloor.