146 to 65 million years ago Uplift and erosion continued throughout the Cretaceous Period. The only Cretaceous rocks found in Missouri are in the Mississippi embayment area of the boot heel. Erosion continued stripping away the Mississippian and Pennsylvanian sediments across the Ozark Dome.
In the west, major mountain building continued all along the edge of the North American and throughout the Rocky Mountain area. In the east, rifting continued as Europe and Africa split away from North America to form the Atlantic Ocean and the Gulf of Mexico.
By the end of the Cretaceous, the North American continent had moved to the north placing the Ozarks at near its current latitude.
The dinosaurs continued to thrive and dominate during
the Cretaceous. However, at the very end of the Cretaceous the dinosaurs
and a large number of other species were wiped out in another mass extinction.
This extinction event was the result of a large meteorite impact that
struck the coast of the Yucatan peninsula.