Write major geological events of mesozoic era
1. Triassic-Jurassic extinction event (approx. 201 million years ago): The first major extinction event of the Mesozoic era, which wiped out around 20% of all marine species and many reptile species.
2. Formation of Pangea (approx. 299-200 million years ago): During the early and middle portions of the Mesozoic era, the supercontinent Pangea was formed as the Earth's tectonic plates slowly shifted and collided.
3. Jurassic-Cretaceous extinction event (approx. 145 million years ago): The second major extinction event, which eliminated many species of marine reptiles and ammonites, as well as several species of dinosaurs.
4. Development of flowering plants (approx. 140 million years ago): During the Cretaceous period, flowering plants (angiosperms) began to diversify and spread across the Earth, leading to the evolution of many new species of insects and mammals.
5. Seafloor spreading and the formation of mid-ocean ridges (approx. 150 million years ago): As the Earth's tectonic plates continued to move, new ocean crust was formed at mid-ocean ridges, leading to the eventual breakup of Pangea and the formation of the modern continents.
6. Rise of the dinosaurs (approx. 230-65 million years ago): The Mesozoic era is perhaps most famous for the evolution and dominance of the dinosaurs, which diversified into a wide variety of shapes and sizes and thrived for millions of years before being wiped out by the Cretaceous-Paleogene extinction event.
The Mesozoic Era, which lasted from approximately 252 million to 66 million years ago, is divided into three major periods: the Triassic, Jurassic, and Cretaceous periods. Within these periods, numerous significant geological events occurred. Here are some of the major events of the Mesozoic Era:
1. Triassic Period (252-201 million years ago):
a. Pangea Breakup: During the early Triassic, the supercontinent Pangea started to break apart, leading to the formation of separate landmasses that would later evolve into the continents we know today.
b. Mass Extinction: Towards the end of the Triassic, a major extinction event occurred, known as the Triassic-Jurassic extinction event. It led to the extinction of approximately 80% of marine species and significant terrestrial fauna, allowing for new evolutionary opportunities in the Jurassic.
2. Jurassic Period (201-145 million years ago):
a. Diversification of Dinosaurs: The Jurassic saw the rise and diversification of dinosaurs, with iconic genera like Stegosaurus, Brachiosaurus, and Allosaurus appearing.
b. Formation of the Atlantic Ocean: As Pangea continued to separate, the Atlantic Ocean began to form as new oceanic crust formed between the continents.
c. Evolution of Birds: Late in the Jurassic, theropod dinosaurs evolved feathers, hinting at the origins of birds.
3. Cretaceous Period (145-66 million years ago):
a. Expansion and Dominance of Dinosaurs: Dinosaurs became the dominant terrestrial creatures during the Cretaceous, with groups like Tyrannosaurus rex, Triceratops, and Velociraptors evolving.
b. Flowering Plant Radiation: The Cretaceous witnessed a dramatic increase in diversity and dominance of flowering plants, or angiosperms, which led to the development of more complex ecosystems.
c. K-Pg Mass Extinction: The Cretaceous-Paleogene extinction event (K-Pg) occurred at the end of the Cretaceous period, resulting in the extinction of dinosaurs and many other species. This event is most famously associated with the impact of a large asteroid or comet near the present-day Yucatán Peninsula in Mexico.
These events shaped the Earth's landscape and ecosystems during the Mesozoic Era, setting the stage for the succeeding Cenozoic Era.