Mesozoic

The Mesozoic was a long era in Earth’s history that lasted from about 252 to 66 million years ago. It is often called the Age of Reptiles because dinosaurs and many other reptiles were common on land, in the oceans, and in the skies. The Mesozoic came after the Paleozoic Era and before the Cenozoic Era, and it was divided into three major periods: the Triassic, Jurassic, and Cretaceous.

During the Mesozoic, Earth’s continents were not in the same places they are today. At the start of the era, most land was joined together in one large continent called Pangaea. Over millions of years, Pangaea slowly broke apart. This process changed the shapes of oceans and continents, creating new environments such as shallow seas, mountains, and forests. These changes affected where plants and animals lived and how they evolved.

Life on Earth changed greatly during the Mesozoic. In the early Triassic Period, many species were recovering from a large extinction that happened at the end of the Paleozoic. As the Mesozoic continued, dinosaurs became one of the most common land animals. Some species were small and fast, while others grew to very large sizes. Flying reptiles called pterosaurs lived in the skies, and marine reptiles such as ichthyosaurs and plesiosaurs lived in the oceans. Early mammals and early birds also appeared during this era, though they were usually small.

Plants also changed during the Mesozoic. At the beginning of the era, many plants produced spores or cones, like ferns and conifers. By the Cretaceous Period, flowering plants began to spread. These plants produced seeds inside fruits and became an important food source for many animals. Fossils from Mesozoic rocks include leaves, pollen, and wood that show how plant life developed over time.

The climate of the Mesozoic was generally warmer than today, with fewer ice-covered regions. Some areas were dry deserts, while others had large forests. These different climates supported many types of ecosystems. Scientists study rock layers, fossils, and ancient soils to understand what conditions were like during this era.

The Mesozoic ended about 66 million years ago with a major mass extinction event. Many species disappeared, including all non-bird dinosaurs. Many scientists think this event was caused by a large asteroid impact combined with volcanic activity and climate changes. After the extinction, new groups of animals, such as mammals, became more common in the Cenozoic Era. The Mesozoic remains an important era for studying how life and Earth’s surface changed over millions of years.