- noting or pertaining to an era occurring between 230 and 65 million years ago, characterized by the appearance of flowering plants and by the appearance and extinction of dinosaurs.
- the Mesozoic Era or group of systems.
- of, denoting, or relating to an era of geological time that began 250 000 000 years ago with the Triassic period and lasted about 185 000 000 years until the end of the Cretaceous period
- the Mesozoic the Mesozoic era
adj.1840, from Greek mesos “middle” (see meso-) + zoe “life” (see zoo) + -ic. Name coined by British geologist John Phillips for the fossil era “between” the Paleozoic and the Cenozoic.
- The era of geologic time from about 245 to 65 million years ago. The Mesozoic Era was characterized by a drastic change in plants and animals. In the early part of the Mesozoic, ferns, cycads, and ginkgos were dominant; later, gymnosperms and angiosperms developed. Dinosaurs also first appeared in the Mesozoic and, with the exception of birds, became extinct at the end of the era. See Chart at geologic time.