Fig. 1.

Principal areas where Tertiary relict floras occur, and Tertiary land bridges between Eurasia and N America. The route shown for the N Atlantic land bridge is the ‘Greenland–Faeroes bridge’ (Xiang et al., 2005), the only connection that might have persisted after 40 Myr ago (see Milne and Abbott, 2002). Before this time, a second more northerly connection existed between Greenland and Scandinavia (for a detailed description, see Tiffney, 1985b). The Bering land bridge existed for most of the tertiary period but moved progressively southwards throughout this period, and was well within the Arctic Circle in the early to middle Tertiary (Milne and Abbott, 2002). Many references treat E Asia as a single area, but this figure follows Donoghue et al. (2001) and Milne and Abbott (2002) in separating northern and southern parts of this refugial area.