Ordovician in the Paleozoic
The four eras of geological time
|Updated June 01, 2013
There are 4.55 billion years, the dust of ancient giant stars are proto solar nebula rotated about what will become of our Sun.
At this point resembles the young Earth, a huge ball molten rock.
Geological time span of today, there are 4.55 billion years, time of the birth of the Earth.
Image: The geological eons of Earth, the Hadean to now, the Phanerozoic.
The Ordovician is the second of six geological systems constituting the Paleozoic located himself in the last geological eon, the Phanerozoic. It takes 45 million years and extends from -488.3 ± 1.7 to -443.7 ± 1.5 million years.
Life in the Ordovician
The first explosion of life date from the Cambrian (-542 to -488 million years) with the emergence of the main current animal living in the seabed. But it was in the Ordovician that the oceans are full of life with a truly exceptional increase in the number of marine organisms.
The Ordovician period is known as one of particular interest to life.
Image: Limestone in trilobites, brachiopods, corals, gastropods (Lower Silurian), Anticosti Island, Quebec, Canada.
Mass extinction of the Ordovician
The Ordovician was a time of giving shallow inland sea rich in life, animal life existed only in the sea but there are about 440 to 445 million years, at the boundary between the Ordovician and Silurian two mass extinctions occur.
Image: Mass extinctions according Raupp, D.M. 1993.