<P> During this period, mammals and birds continued to evolve into roughly modern forms, while other groups of life remained relatively unchanged . Early hominids, the ancestors of humans, appeared in Africa near the end of the period . Some continental movement took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene . This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean . The global climate cooled considerably over the course of the Neogene, culminating in a series of continental glaciations in the Quaternary Period that follows . </P> <P> In ICS terminology, from upper (later, more recent) to lower (earlier): </P> <P> The Pliocene Epoch is subdivided into 2 ages: </P> <Ul> <Li> Piacenzian Age, preceded by </Li> <Li> Zanclean Age </Li> </Ul>

The uppermost epoch of the neogene period is