time period of the earth
New Geological Period. In March 2004, geologists added a new time period to Earth's chronologyâthe Ediacaran Period. The Ediacaran Period lasted about 50 million years, from 600 million years ago to about 542 million years ago.It was the last period of the Precambrian's Neoproterozoic Era.Multicelled organisms first appeared during this time. This period is the first new one added in 120 years.he Ediacaran Period lasted about 50 million years, from 600 million years ago to about 542 million years ago. It was the last period of the Precambrian's Neoproterozoic Era. Multicelled organisms first appeared during this time.