Messinian

The Messinian is a term used in the study of Earth's history to describe the last part of the Miocene epoch, which happened between about 7.25 million and 5.33 million years ago. It came after the Tortonian and was followed by the Zanclean, the first age of the Pliocene.

This time period is important because it matches with certain stages in the evolution of land animals in Europe, known as the Turolian, and in Central Europe, called the Pontian. It also lines up with later stages in South America, called the Huayquerian and Montehermosan, and an earlier stage in North America known as the Hemphillian.

One of the most famous events of the Messinian was the Messinian salinity crisis. Around 6 million years ago, the Mediterranean Sea dried up and refilled many times, changing the environment and affecting many forms of life.

Definition

The Messinian was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1867. Its name comes from the Italian city of Messina on Sicily, where a special kind of rock layer was found.

The start of the Messinian is marked by the first appearance of a tiny sea creature called a planktonic foram. The end of the Messinian is marked by changes in tiny sea creatures called nanoplankton.

Palaeoclimatology

In South Asia, the early part of the Messinian period, up until about 6 million years ago, saw major drying. This change turned the area from mostly C₃ forests and woodlands into C₄ savannas.

In Namibia, the Messinian period marks a shift from the wetter Tortonian climate to the drier Zanclean climate that followed.