The Cenozoic and Paleozoic ERAS are two of the three major divisions of geologic time. The Cenozoic ERA, which began about 65 million years ago, is divided into the Neogene Period (7 letters) and the Quaternary Period (4 letters). The Paleozoic ERA, which began about 541 million years ago, is divided into the Cambrian Period (3 letters), the Ordovician Period (6 letters), the Silurian Period (6 letters), the Devonian Period (6 letters), the Carboniferous Period (10 letters), and the Permian Period (7 letters). The EOCENE Epoch (6 letters) is part of the Neogene Period of the Cenozoic ERA.