Medical dictionary definition of AF as a medical term including diseases, symptoms, treatments, and other medical and health issues. About Us Bookmark this page
Dinosaurs lived between 230 and 65 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared. Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous.inosaurs lived between 230 and 65 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared. Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous.
The first mammal-like reptiles occurred during the Permian Period, about 300 million years ago. Primitive mammals appeared in the Mesozoic Era along with dinosaurs in the Jurassic Period, about 250 million years ago. The Age of Mammals began after the extinction of the dinosaurs and beginning of the Cenozoic Era during the Quaternary Period, about 65 million years ago. socratic Subjects