The fossil record of dinosaurs in Africa extends from the Late Triassic Period, over 200 million years ago, until the Late Cretaceous Period, presumably 65 million years ago. However, the extinction event that ended the reign of dinosaurs has yet to be documented. Throughout this length of time, Africa remained relatively stable geologically, changing position only slightly by drifting and rotating northward. By contrast, the continents surrounding Africa moved greatly, resulting in ocean barriers between what were once contiguous land masses. The changing geography of Africa and its neighbours throughout the Mesozoic Period is fundamental to understanding the dinosaur fossils found there.