By the late Cretaceous, the continents were beginning to assume their broad modern alignment. The Americas were drifting westwards, causing the Atlantic Ocean to widen. India was still in the early stages of its northward migration, berthed alongside Madagascar. Australia was still attached to the Antarctic residue of the ancient supercontinent of Gondwanaland. Manchuria/China was yet to collide with Siberia, and the continents of the northern hemisphere were, as yet, separated from their southern counterparts by a sinuous Tethys Ocean. Snaking up from Tethys, the Western Interior Seaway bisected the North American continent, and Greenland remained attached to the landmasses of both North America and Europe. The climate had cooled appreciably since the early Cretaceous, marked by the spread of flowering plants and deciduous forest. Dinosaurs remained the dominant life forms on land, sea and in the skies, but their sudden extinction was on the horizon.
— OR —