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Figure 5: The furthest extents of Pleistocene glaciation superimposed on the current and partial paleodistribution of foxsnakes. Notice that the current distribution (shaded area) is completely within the Pleistocene ice sheet coverage. The different colored lines represent the furthest extents of the four classical subdivisions of the Quaternary glaciations in North America. Nebraskan 1 mya – 950 kya, Kansan 750 kya – 650 kya, Illinoian 350 kya – 250 kya, Wisconsin 125 kya – 10 kya.