GEOLOGY

Detailed explanation-1: -New research led by scientists from Oxford University and Exeter University has shown that the invasion of the land by plants in the Ordovician Period (488-443 million years ago) cooled the climate and triggered a series of ice ages.

Detailed explanation-2: -For the most part the Earth’s climate was warm and wet, with sea levels rising as much as 1, 970 feet (600 meters) above those of today. But once Gondwana took up its polar position in the late Ordovician, massive glaciers formed over Africa at the supercontinent’s center.

Detailed explanation-3: -Numerical models of the Ordovician atmosphere estimate that levels of carbon dioxide were several times higher than today. This would have created warm climates from the Equator to the poles; however, extensive glaciation did occur for a brief time over much of the Southern Hemisphere at the end of the period.

Detailed explanation-4: -During the Ordovician, many new species replaced their Cambrian predecessors. In addition, primitive plants called lycophytes began to move onto land, which was barren until then. Later, in the Devonian, other types of plants colonized terrestrial habitats.