Figure 2 in Evaluating hypotheses on the origin and diversification of the ringneck snake Diadophis punctatus (Colubridae: Dipsadinae)

Figure 2. Simplified tree with the mean dates of origin (in millions of years) for each of the major lineages and haplogroups. Numbers below nodes refer to Table 2. Letters above nodes refer to the optimal reconstructions of ancestral areas; A, Coast Plain east of the Mississippi; B, North-eastern USA; C, west of the Mississippi River to the Rocky Mountains; D, west of the Rocky Mountains; E, Mexico.