In the Pleistocene Epoch, the Philippines was connected to the large continent of Asia by land bridges that many times were underwater. But as the sea levels rose and fell, land bridges were exposed. These became the paths by which large migrating mammals found their way to the Philippines from Indonesia or as far away as New Guinea. One of these mammals was the Elephas Sp. It stood about 10 to 12 feet tall and is very similar to the elephant we now know. The other was the Stegodon Sp., a much older cousin of the Elephas Sp. They roamed the area we now know as the Cagayan Valley together with other mammals such as the rhinoceros, giant land turtles with flat carapaces (Ed. This is the protective shell on the back of turtles), wild pigs, deer and eventually, man.