Pliocene

Part of speech: noun

Definitions

1. A geological epoch between the Miocene and Pleistocene occurring approximately 5.3 to 2.6 million years ago; it is characterized by significant climatic changes and the development of modern fauna; this period marked the formation of many landforms and ecosystems present today
2. This epoch, spanning from 5.3 to 2.6 million years ago, is notable for its climatic shifts and the evolution of species that resemble current forms; significant geological activity also defined this era, influencing present landscapes and habitats
3. Encompassing the time frame from 5.3 to 2.6 million years ago, this geological epoch was marked by major climate changes and the emergence of modern flora and fauna; it also played a pivotal role in shaping many geographic features we recognize today

Etymology: The name "Pliocene" was built from two Greek words meaning "more new." Geologists of the 1830s were sorting rock layers by how many of their fossil shells still belonged to living species. The Greek "pleíōn" means "more," and "kainós" means "new," so the label described a period in which a larger share of the animals resembled those alive today than in earlier epochs. The word was coined in 1831 by William Whewell, an English philosopher and historian of science, and given to the epoch by Charles Lyell, who introduced it in his 1833 book "Principles of Geology." Lyell used the name to mark a stage of the Tertiary rocks in which the proportion of living mollusc species was higher than in the stage before it. Its later boundaries, set at roughly 5.3 and 2.6 million years ago, were drawn from far more evidence than Lyell had at hand.