Friday, October 28, 2011











This is Earth in the Late Cambrian period.










This is Earth in the Mid-Ordovician period.














This is Earth in the Late Ordovician period.










This is Earth in the Early Silurian period.










This is Earth in the Early Devonian period.










This is Earth in the Mid-Devonian period.










This is Earth in the Early Carboniferous period.