Phanerozoic

The Phanerozoic ( ancient Greek φανερός phaneros "visible" ζῷον Zoon " creatures ", so about the "age of the visible life" ) is the youngest eon in Earth's history and continues to this day. The term " Phanerozoic " is a term biostratigrafischer structure; the division into individual stratigraphic sections is based on index fossils.

The Phanerozoic follows the Proterozoic eons, Archean and Hadean, which are collectively referred to as the Precambrian. The Phanerozoic is divided into three eras: the Paleozoic ( Palaeozoic ), Mesozoic ( Mesozoic ) and Cenozoic ( Cenozoic ). Thus, it covers the period from about 541 million years before present to the present.

Structure

The Phanerozoic is divided into the following Äratheme:

• Eon: Phanerozoic ( 541-0 mya ) Era: Cenozoic ( 66-0 mya )
• Era: Mesozoic Era ( 252.2 to 66 mya )
• Era: Paleozoic Era ( 541 to 252.2 mya )

The concept

The origin of the term " Phanerozoic " is due to the fact that, from the Cambrian - the lowest system ( = earliest time period) of the Paleozoic era - the first visible fossil remains occur in great numbers, not only in the microscope. From the Precambrian, although fossil remains are still preserved, however, these are recognized in the rule only with microscopic methods (an exception is the Ediacaran fauna). The period of the Precambrian in which life emerges for the first time on earth, whose youngest eon, the Proterozoic ( πρότερος Proteros " previous ", " early", "age of the earliest living things "). This was formerly called Kryptozoikum ( κρυπτός kryptós " hidden ").