Miocene

The Miocene is a geologic epoch of the Neogene Period in the Cenozoic Era, spanning from about 23.03 million years ago to about 5.333 million years ago. The name derives from Greek meiōn, meaning “less” or “more distant,” and kainos, meaning “recent,” reflecting its position farther back in time than more recent epochs. It follows the Oligocene and is succeeded by the Pliocene. The Miocene is commonly divided into Early, Middle, and Late intervals, with regional and faunal differences.

Climate and environments during the Miocene varied considerably. Early Miocene climates were relatively warm, supporting extensive forests in many regions. Over time, global cooling and drying intensified, contributing to the expansion of grasslands and a shift toward more open habitats in many areas. These environmental changes influenced the evolution and distribution of many animal groups, including grazing mammals such as horses and bovids, as well as diverse marine and terrestrial fauna.

Biodiversity and evolution flourished in the Miocene. It witnessed significant diversification of many mammal groups, including early ancestors of modern whales, as well as expansion and turnover among apes in Africa and Asia. The epoch also saw ongoing tectonic activity that influenced climate and geography, including the uplift of mountain systems and changes in ocean currents.

A notable late-Miocene event is the Messinian Salinity Crisis (approximately 5.96–5.33 Ma), when the Mediterranean Sea largely evaporated due to isolation from the Atlantic. The subsequent Zanclean flood refilled the basin as the epoch ended and the Pliocene began. The Miocene laid important groundwork for later evolutionary and climatic developments.