Phanerozoic I: Palaeozoic is the seventh studio album by German post-metal band the Ocean. It is a concept album exploring the Phanerozoic geological eon, with each track title referencing a period of the Paleozoic era. Phanerozoic I: Palaeozoic was released worldwide on 2 November 2018. It is the first of two volumes; the latter, Phanerozoic II: Mesozoic / Cenozoic, was released separately in 2020.