Cretáceo

The Cretaceous Period, often referred to as the Cretáceo in Spanish and Portuguese, was the third and final period of the Mesozoic Era. It began 145 million years ago and ended 66 million years ago. This period is known for its dramatic geological and biological changes. The supercontinent Pangaea continued to break apart, leading to the formation of the Atlantic Ocean and the separation of the continents into their modern configurations. This continental drift significantly influenced global climate and ocean currents.

Biologically, the Cretaceous was a time of immense diversity and evolution. Flowering plants, or angiosperms, first appeared and rapidly diversified, becoming a dominant feature of terrestrial ecosystems. This had profound impacts on herbivore evolution, leading to the development of specialized feeding adaptations. The period is perhaps most famous for its dinosaurs. Large herbivorous dinosaurs like hadrosaurs and ceratopsians were abundant, as were formidable predators such as tyrannosaurs. Pterosaurs continued to soar through the skies, and the oceans teemed with marine reptiles like mosasaurs and plesiosaurs. Birds also underwent significant evolution during this time, with many modern bird groups emerging.

The end of the Cretaceous Period is marked by a major mass extinction event, the Cretaceous-Paleogene (K-Pg) extinction. This event wiped out approximately 75% of all species on Earth, including all non-avian dinosaurs. The leading theory for this extinction is a catastrophic asteroid impact, though volcanic activity may have also played a role. The demise of the dinosaurs paved the way for the rise of mammals in the subsequent Cenozoic Era.