British geologist John Phillips proposed the name Kainozoic in 1840. He derived this term from Ancient Greek words meaning new life to describe systems of organic forms traceable in Earth's stratified crust.
The International Commission on Stratigraphy officially recognized the Quaternary Period in June 2009. Before this decision, scientists grouped the timeline into three periods: Paleogene, Neogene, and Quaternary.
India collided with Asia around 50 million years ago creating the Himalayas. Arabia also collided with Eurasia closing the Tethys Ocean and forming the Zagros Mountains during this era.
Earth entered a period of long-term cooling around 34 million years ago causing permanent ice to build up on Antarctica. The Antarctic Circumpolar Current formed between Australia and Antarctica in the Mid-Eocene disrupting climate patterns and shrinking tropical jungles.
Modern placental mammals originated during the Paleocene Epoch between 66 million and 56 million years ago. Early primates whales and horses evolved alongside many other mammal forms in dense forests during this time.
Homo sapiens appeared roughly 100,000 years ago after a severe drought ended in Africa. Human activity triggered a mass extinction beginning roughly 10,000 years ago known as the Sixth Extinction with over 322 recorded species becoming extinct due to human actions since the Industrial Revolution.