Introduction to the Cretaceous Period
The Cretaceous period, spanning from approximately 145 to 66 million years ago, was the final chapter of the Mesozoic Era, often referred to as the "Age of Dinosaurs." This period saw the peak of dinosaur diversity and dominance, with iconic species like Tyrannosaurus rex, Triceratops, and Velociraptor thriving across the globe.
The Cretaceous ended with the Cretaceous-Paleogene (K-Pg) extinction event, which wiped out nearly 75% of all species, including non-avian dinosaurs. This event marked the end of the Mesozoic Era and the beginning of the Cenozoic Era, often called the "Age of Mammals."
Iconic Dinosaurs of the Cretaceous
The Cretaceous period is famous for its diverse and iconic dinosaurs, including:
- Tyrannosaurus rex: One of the largest carnivorous dinosaurs, known for its massive skull and powerful jaws.
- Triceratops: A large herbivore with three horns and a bony frill, often depicted in battles with T. rex.
- Velociraptor: A small, agile predator known for its sharp claws and intelligence.
- Ankylosaurus: A heavily armored herbivore with a club-like tail for defense.
Ecosystems of the Cretaceous
The Cretaceous ecosystems were rich and diverse, with dinosaurs occupying a wide range of niches. Flowering plants (angiosperms) emerged during this period, providing new food sources for herbivorous dinosaurs. Theropods like T. rex and Velociraptor were apex predators, while herbivores like Triceratops and Ankylosaurus dominated the landscape.
Marine reptiles like Mosasaurus and Plesiosaurus ruled the oceans, while flying reptiles like Pteranodon and early birds like Ichthyornis dominated the skies.
Climate and Geography
The Cretaceous climate was generally warm, with high sea levels creating shallow inland seas. The breakup of Pangaea continued, leading to the formation of modern continents. The warm climate and abundant vegetation supported a wide variety of life, from small mammals to massive dinosaurs.
The Cretaceous ended with a catastrophic asteroid impact, which caused global climate change and led to the extinction of the dinosaurs. This event allowed mammals to diversify and eventually dominate the Earth.