Mesozoic Era

Cretaceous Period

145–66 Million Years Ago

The longest period of the Mesozoic, the Cretaceous saw dinosaurs reach their peak diversity. Tyrannosaurus rex, Triceratops, and Velociraptor are among its most iconic inhabitants. Flowering plants (angiosperms) appeared and rapidly diversified, transforming terrestrial ecosystems. The period ended 66 million years ago when the Chicxulub asteroid impact triggered the K–Pg mass extinction.

Environment

Climate & Environment

One of the warmest periods in Earth's history. Sea levels were at their highest, flooding large portions of continents. No permanent polar ice existed for most of the period.

Fauna & Flora

Signature Life Forms

Tyrannosaurus rex — iconic apex predator

Triceratops and other ceratopsians

Rise of flowering plants (angiosperms)

Mosasaurs — giant marine lizards