Which of the following best describes a characteristic of the Mesozoic era?

The Mesozoic era, often referred to as the "Age of Reptiles," is characterized by the dominance of reptiles, particularly dinosaurs, which were the major terrestrial vertebrates during this time. The Mesozoic is divided into three periods: the Triassic, Jurassic, and Cretaceous, each of which saw significant evolutionary advancements in reptilian species. This era is notable for the diversity and ecological prevalence of reptiles in various environments, making them the most prominent vertebrates on Earth during this time.

While other features did exist during the Mesozoic, such as the development of flowering plants towards the end of the era, the reign of dinosaurs and other reptiles greatly defines this geological period. Mammoths and ice sheets, on the other hand, are associated with much later geological periods, specifically the Pleistocene epoch and the more recent Quaternary period. This context emphasizes the unique ecological landscape of the Mesozoic, where reptiles were the major land animals.