The Age of Dinosaurs

The age of dinosaurs, geologically known as the Mesozoic Era, lasted approximately 180 million years from approximately 252 million years ago to 66 million years ago. The Mesozoic Period began after Earth's worst-ever extinction event devastated life. The Permian-Triassic extinction event, also known as the Great Dying, took place roughly 252 million years ago and was one of the most significant events in the history of our planet. This extinction event wiped out about 90% of marine species and 70% of terrestrial vertebrate species.

Throughout this Era, dinosaurs diversified into a wide range of sizes, shapes, and ecological niches, dominating terrestrial ecosystems and leaving behind a rich fossil record that continues to captivate scientists and enthusiasts alike. Early mammals, reptiles, and archosaurs, a group of dinosaurs and their relatives, also flourished during this Era.

There were three major periods of this Mesozoic Era- the Triassic, Jurassic, and Cretaceous periods.

01. Triassic Period (Approx. 252 to 201 million years ago): The Triassic Period marked the beginning of remarkable changes that were to take place throughout the Mesozoic Era, particularly in the distribution of continents, the evolution of life, and the geographic distribution of living things.

The early Triassic was marked by harsh environmental conditions following the Permian extinction, including widespread deserts and volcanic activities. The Earth's landmasses were joined in the supercontinent- Pangaea, surrounded by the Panthalassic Ocean. During this period the supercontinent began to break apart, and life began to recover, with the emergence of new species of plants, insects, and marine organisms. The first dinosaurs appeared during the late Triassic. But they were yet to become the dominant animals on Earth. Other notable organisms included early mammals, reptiles, and the archosaurs, a group of dinosaurs' relatives.

02. Jurassic Period (201 to 145 million years ago): The Jurassic Period is a 56 million chunk of the Mesozoic Era. Named for the Jura Mountains on the border between France and Switzerland, where rocks of this age were first studied, the Jurassic has become a household word with the success of the movie Jurassic Park. 

This time is known for its lush fern forests, diverse marine life, and the rise of dinosaurs on land. This period saw the peak of dinosaur diversity and dominance. Iconic dinosaurs roamed the Earth during this time. Amongst them, the largest land animals of all time were the gigantic sauropods herbivorous (Diplodocus, Brachiosaurus, and Apatosaurus were members of this family) and Stegosaurus. Predatory dinosaurs of the Jurassic included fearsome carnosaurs such as Allosaurus, smaller, faster coelurosaurs, and ceratosaurs such as Dilophosaurus. The Jurassic also saw the origination of the first birds, including the well-known Archaeopteryx. Alongside them, early mammals, and flowering plants also appeared during the Jurassic period.

03. Cretaceous Period (145 to 66 million years ago): Cretaceous Period is the last period in the Mesozoic Era. It lasted after the Jurassic Period and before the Paleogene - the first period of the Cenozoic Era, our current era. During the Cretaceous, Earth's climate was generally warmer than today, with high sea levels and extensive shallow seas covering many parts of the continents. The breakup of the supercontinent Pangaea continued during this period, leading to the formation of separate landmasses and oceans. The climate was generally warm and humid supporting lush vegetation and diverse ecosystems.

The Cretaceous Period saw the expansion of new ecosystems, including the rise of flowering plants and the diversification of terrestrial and marine life. Dinosaurs continued to thrive and diversify during the Cretaceous, with many iconic species emerging. The carnivorous dinosaurs like Jurassic Park star Tyrannosaurus rex, Triceratops, and Velociraptor and large herbivores like the duck-billed hadrosaurs and the armored ankylosaurs lived during this period.

However, the Cretaceous-Tertiary (K-T) extinction event occurred around 66 million years ago, marking the end of the Mesozoic Era as well as the reign of dinosaurs. It's widely believed that this event, possibly caused by an asteroid impact, led to the extinction of non-avian dinosaurs and many other species, paving the way for the rise of mammals and birds.

These periods of the Mesozoic Era saw the rise and fall of various dinosaur groups, with their evolution shaped by environmental changes and interactions with other organisms. Studying the dinosaur ages provides valuable insights into Earth's history and the processes that have shaped life on our planet.

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