Tortonian

The Tortonian is a time period in the geologic time scale that was part of the late Miocene. It lasted from about 11.6 million years ago to 7.2 million years ago. This stage came after the Serravallian and was followed by the Messinian.

During the Tortonian, many important changes were happening on Earth. It overlapped with several regional stages and land mammal ages in different parts of the world. This includes the Pannonian Stage in Central Europe, as well as various land mammal ages in Europe, North America, and South America. The Tortonian helps scientists understand how life and Earth’s surface were changing during this part of history.

Definition

The Tortonian was named by a Swiss scientist called Karl Mayer-Eymar in 1858. He chose the name after the Italian city of Tortona in the Piedmont region.

The Tortonian is identified by small fossils found in rocks. It represents a particular time in Earth's past, helping scientists learn about changes to our planet over millions of years.

Geologic history

Geologists found two big volcanic eruptions linked to the Yellowstone hotspot. One of these was the largest eruption in that area. It happened about 8.72 million years ago.

About 10 million years ago, deep water from the North Atlantic started flowing more into the Indian Ocean.