Editing Swamp rabbit (section)

=== Fossil record ===
''Sylvilagus aquaticus'' [[fossil]]s have been identified as early as the [[Pleistocene]] epoch, with a 1940 discovery of [[Molar (tooth)|molar]] teeth found in a [[Missouri]] deposit dating back to that era.<ref name="Chapman-1981" /> [[Glaciations]] from the [[Illinoian (stage)|Illinoian]] stage (a geological period in North America ranging from {{Ma|.191|.130}}) likely created [[Refugium (population biology)|refugia]] that led to the emergence of the swamp rabbit as a distinct species. Glacial movements in the late Pleistocene (during and after the Illinoian) created a [[hybrid zone]] in western Georgia, which likely led to the separation of the swamp rabbit from the [[marsh rabbit]] (''S. palustris''), its closest relative.<ref name="Nielsen-2018" />