Mesozoic

Part of speech: adjective, noun

Definitions

1. A major geological era situated between the Paleozoic and Cenozoic, noted for the prevalence of reptiles and the evolution of dinosaurs
2. This historical period falls between two significant eras, showcasing the dominance of reptiles and the beginnings of birds and mammals
3. A geological era that lies between the Paleozoic and Cenozoic eras, characterized by the rise of dinosaurs and the emergence of early mammals and birds

Etymology: Mesozoic is a coinage built from two Greek elements: "mesos" meaning "middle" and "zoe" meaning "life," with the adjectival ending "-ikos" (rendered as "-zoic" in English). Its name thus means "middle life," a label that was chosen to sit between two earlier eras of animal existence, the Palaeozoic and the Cenozoic. The term refers to the geological era spanning roughly the Triassic, Jurassic and Cretaceous periods, the age when dinosaurs dominated the land. The word was not used by ancient Greeks, who had no concept of this geological time scale. It was coined in the 19th century by geologists who were building a standardized system of divisions for the history of life on Earth. The naming pattern follows the earlier "Palaeozoic" (ancient life), which had been established a few decades before, so "Mesozoic" was a deliberate placement in a sequence rather than an independent description.