Which part of the Earth's history is characterized by the dominance of reptiles?

The time period marked by the dominance of reptiles is known as the Mesozoic Era. This era, which spanned from approximately 252 to 66 million years ago, is often referred to as the “Age of Reptiles” due to the variety and abundance of reptiles, including dinosaurs, that thrived during this time. The Mesozoic Era is further divided into three periods: the Triassic, Jurassic, and Cretaceous, each showcasing various evolutionary developments among reptiles.

During the Mesozoic, reptiles dominated terrestrial ecosystems, evolved into many forms, and adapted to various environments. The evolution of birds and the diversification of mammals began during the late stages of this era, but the hallmark of this time remained the prevalence and variety of reptilian species.

In contrast, the Cenozoic Era that follows the Mesozoic is often noted for the emergence and dominance of mammals and birds after the mass extinction event that wiped out many reptiles. The Paleozoic Era is characterized by the rise of fish, amphibians, and early reptiles, while the Archean Era represents a much earlier time in Earth’s history, focused on the formation of the planet and the origins of life, featuring largely microbial life. Thus