The Aquitanian is, in the ICS' geologic timescale, the oldest age or lowest stage in the Miocene. It spans the time between 23.03 ± 0.05 Ma and 20.43 ± 0.05 Ma (million years ago). The Aquitanian succeeds the Chattian (the youngest age of the Oligocene) and precedes the Burdigalian. The Aquitanian age overlaps with the Harrisonian, Agenian, Pareora, Landon, Otaian, and Waitakian ages from various regional timescales.