Lutetian

The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between 48.6±0.2 and 40.4±0.2 Ma. The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the Middle Eocene subepoch. Less often, the Middle Eocene is not used and the Lutetian is united with the Ypresian in the Early Eocene.