Geological Time Periods Reclassified - Welcome To The Ediacaran - BBC

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Geologists have added a new period to their official calendar of Earth's history - the first in 120 years. The Ediacaran Period covers some 50 million years of ancient time on our planet from 600 million years ago to about 542 million years ago. It officially becomes part of the Neoproterozoic, when multi-celled life forms started to take hold on Earth.

However, Russian geologists are unhappy their own title - the Vendian - which was coined in 1952, was not chosen. The decision was taken after a fifteen-year long period of consideration by expert geologists.

"There's always been a recognition that the last part of the Precambrian is a special time before the first shelled animals, when there are these mesh-like creatures of uncertain affinity," Professor Jim Ogg, secretary-general of the International Commission on Stratigraphy (ICS), told BBC News Online.

EDIT

The Ediacaran begins at the end of the last ice age of the Snowball Earth, or Cryogenian Period, a term given to a series of glaciations that covered most of our planet between 850-630 or 600 million years ago. One theory proposes that these climate shocks triggered the evolution of complex, multi-celled life."

EDIT

http://news.bbc.co.uk/2/hi/science/nature/3721481.stm