Mesozoic

The Mesozoic Era (Greek μέσος mesos, middle ',' middle ' and ζῶ zo, life '), also Mesozoic or Erdmittelzeit, is a eon, which began about 252.2 million years ago and ended about 66 million years ago. It is divided into the Triassic, Jurassic and Cretaceous. The Mesozoic Era is within the Earth's history, the average period of the Phanerozoic. In this aeon the Mesozoic followed the Paleozoic Era ( Paleozoic ) and is detached from the Cenozoic ( Cenozoic ).

Classification of the Mesozoic

Position of the Mesozoic era in the Phanerozoic:

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

The Mesozoic Era is divided into the following systems ( above the youngest, the oldest below ):

• Era: Mesozoic Era ( 252.2 to 66 mya ) System: Cretaceous ( 145-66 mya )
• System: Jurassic ( 201.3 to 145 mya )
• System: Triassic ( 252.2 to 201.3 mya )

Life in the Mesozoic

The Mesozoic Era began after an ecological disaster (Permian - Triassic boundary ) at the end of the Permian ( also the end of the Paleozoic ), whose cause has not yet been elucidated; of all animal and plant species died out between 75% and 90% at this largest known mass extinction of Earth's history. This allowed the evolution of a new fauna and flora.

The dinosaurs emerged, dominated the earth and died ( with the exception of birds) from. Your next today's relatives are the crocodiles.

It also developed pterosaurs and a whole host of marine reptiles that became extinct, however all again at the end of the Mesozoic.

In addition, the first small and large mammals, the first flowering plants and most of the trees that we know today appeared.

Evidence indicates that at the end of the Mesozoic a meteoroid struck near the Yucatan Peninsula ( Mexico). This so-called KT- Impact is often blamed for the extinction of 50 % of all plant and animal species - including all dinosaurs, pterosaurs, ammonites, belemnites and most of the time living marine reptiles and birds.

Geology

While at the beginning of the Mesozoic all continents were united into one " super continent " ( Pangaea ), take the end of the Cretaceous period the continents drifting apart gradually its present constellation one.

Climate

Through the successive breaking of the former supercontinent Pangaea in the Mesozoic climate change was a constant subject.

At the beginning of the age, there are still vast deserts, due to the enormous land mass Pangaea - comparable to the Sahara in Africa today (also see continental climate ).

With the emergence of the Tethys at the beginning of the Mesozoic climate was soon damp, the continents began to split. The climate was tropical and resembled a total worldwide very strong, because the sea was not as it is today divided into the Atlantic, Pacific and Indian Ocean and the ocean currents could be more equitably distributed. Even the poles were free of ice.

Only with the emergence of the Atlantic and the beginning of the disintegration of Pangaea in the Jurassic continents, global ocean currents were interrupted and the global balance of climates did not happen. This can be determined based on the annual rings of petrified wood. Towards the end of the Cretaceous, there was by the lack of global temperature compensation first seasons with cold zones in the north and south of the Earth.