The Cretaceous Period was the final period of the Mesozoic Era, spanning approximately 79 million to 66 million years ago. It is divided into two main stages: the Early Cretaceous (145 million to 100 million years ago) and the Late Cretaceous (100 million to 66 million years ago).
During the Cretaceous Period, the Earth experienced significant geological and biological changes. The breakup of the supercontinent Pangaea continued, leading to the formation of separate landmasses that would eventually resemble the continents we recognize today. This fragmentation altered ocean currents and climates worldwide.
The Cretaceous Period is perhaps most famous for its diverse array of dinosaurs, including iconic species like Tyrannosaurus rex, Triceratops, and Velociraptor. Marine reptiles such as mosasaurs and plesiosaurs also thrived during this time, along with flying reptiles like pterosaurs. In addition to dinosaurs, the Cretaceous saw the rise of flowering plants (angiosperms) and the evolution of modern groups of insects, birds, and mammals.
The end of the Cretaceous Period is marked by one of the most significant mass extinction events in Earth’s history, known as the Cretaceous-Paleogene (K-Pg) extinction event. This event, which occurred approximately 66 million years ago, resulted in the extinction of approximately 75% of all species on Earth, including the non-avian dinosaurs. The cause of this mass extinction is widely attributed to a combination of factors, including a large asteroid impact in what is now the Yucatan Peninsula of Mexico and volcanic activity associated with the Deccan Traps in present-day India.
