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.
This is when ancient animals would gradually change forms over a long period of time.the first land animals appear on earth? About 417 million years age during the Devonian era. As for creationism there are skeletons of humans who are much older than 6000 years.ence it is the first plant as well as first animal. Some millions of year back. The first known fossils of what is possibly animal life appear in the Ediacara biota just prior to the Cambrian era.