Pliocène

The Pliocene is a geological epoch that spanned from 5.333 to 2.588 million years ago. It is the most recent epoch of the Neogene Period, which itself is the second of the two periods in the Cenozoic Era. The Pliocene epoch was characterized by a gradual cooling of the Earth and the further expansion of grasslands. The world’s continents were close to their present positions, though they were still drifting slowly. The Isthmus of Panama formed during this epoch, connecting North and South America and allowing for the Great American Biotic Interchange.

Marine and terrestrial life continued to evolve during the Pliocene. In the oceans, many modern forms of marine life were present, with some species becoming extinct and new ones emerging. On land, mammals continued to diversify. Hominin evolution was a significant development, with early human ancestors like Australopithecus living during this time. The flora also changed, with a notable increase in the prevalence of grasses and a decrease in forests in many regions, leading to the expansion of savannah ecosystems.

The climate of the Pliocene was generally cooler and drier than the preceding Miocene epoch, though still warmer than today. Global ice sheets began to expand, particularly in the Northern Hemisphere. Sea levels were also lower than they are today due to the growth of ice sheets. The end of the Pliocene, around 2.588 million years ago, marked the beginning of the Pleistocene epoch, a period dominated by significant glacial cycles. The Pliocene provides a crucial window into understanding the evolutionary pathways of many modern species and the climatic shifts that shaped the planet.