Skip to content
YearMaps

Mesozoic Era · Cretaceous Period

Earth 100 Million Years Ago: The Cretaceous Hothouse

What Earth looked like 100 million years ago: a hot Cretaceous world with high seas, flowering plants and a seaway splitting North America.

Globe of Earth 100 million years ago with a seaway across North America and high sea levelsSpin it in 3D and move through time

Map: Ancient maps: PALEOMAP PaleoDEMs (Scotese & Wright 2018), CC BY 4.0 · Natural Earth.

100 million years ago the world was in a Cretaceous hothouse. There were no ice caps, forests grew near the poles and sea level was far higher than today, perhaps 100 to 250 m.

The Western Interior Seaway flooded the middle of North America, dividing it into two land masses, and shallow seas covered much of Europe and North Africa. Flowering plants were spreading rapidly.

South America and Africa had separated, opening the South Atlantic. India, still attached to Madagascar, was about to break free and race north.

Part of the Mesozoic Era & Age of the Dinosaurs.