The Lutetian is a stage of the Eocene Epoch. It spans the time between 48.6 ± 0.2 Ma and 40.4 ± 0.2 Ma (million years ago). It is usually united with the Bartonian to form the Middle Eocene subepoch. Less often, the Middle Eocene is not used and the Lutetian is united with the Ypresian in the Early Eocene. The Lutetian was named after Lutetia, Latin for Paris.