You are here: Prehistoric > Age of Dinosaurs > Cretaceous Period

Cretaceous Period

Tyrannosaurus rexThe Cretaceous Period, the last part of the Mesozoic Era, extended from 145 to 66 million years ago. As the supercontinents of Laurasia and Gondwana continued to drift apart, each landmass carried its own dinosaur species with it. Cut off from others of their own kind by the sea, dinosaurs began to evolve into different species, adapting to the changing climates wherever they lived. This is the reason why so many new species of dinosaurs appeared during the Cretaceous Period. The ornithischians (“bird-hipped”) become much more abundant, while some slow, lumbering Jurassic sauropods died out. One group of sauropods, the titanosaurs, thrived, however, especially in South America. Some of them were the largest land animals that ever walked the Earth.


Cretaceous world

A map of the world in Cretaceous times A scene in Cretaceous Africa, 112 million years ago. Sarcosuchus (foreground) was a prehistoric crocodile—but, at 12 m (39 ft)...Read More >>A scene in Cretaceous Africa, 112 million years ago. Sarcosuchus (foreground) was a prehistoric crocodile—but, at 12 m (39 ft) almost twice as long as a present-day saltwater crocodile. It probably preyed on Ouranosaurus, a relative of Iguanodon. This dinosaur had a large “sail” on its back, a sheet of skin supported by long, wide spines.
The Cretaceous Period saw the break-up of the great supercontinents, Laurasia and Gondwana, the northern and southern halves of Pangaea, into smaller landmasses. Vast, shallow seas covered much of North America and Europe. Chalk formed from the remains of tiny living things that collected on the beds of these seas.
There was a gradual change in the climate. As the Cretaceous went on, it became cooler and drier. A wide variety of plant life grew in all parts of the world, including Antarctica. Flowering plants, including deciduous trees, which had evolved during the Jurassic, replaced some of the more ancient plant species.

Dinosaurs of Australasia-Antarctica in Early Cretaceous times (when the two continents were linked together) 

The name Cretaceous takes its name from the Latin word for chalk, creta.

WHY IS THE SEA SALTY?


Find the answer