Era Cenozoic Era

Cenozoic Era 9

• 66 Ma Chicxulub Impact Asteroid ends the Mesozoic 10 km asteroid strikes Yucatan; triggers mass extinction.
• 66 Ma End-Cretaceous Extinction K-Pg event — dinosaurs go extinct Chicxulub asteroid impact ends the Mesozoic. Non-avian dinosaurs, mosasaurs and ammonites disappear.
• 56 Ma – 55.8 Ma Paleocene-Eocene Thermal Maximum PETM — rapid global warming Global temperatures rise 5-8 C in under 20,000 years; closest ancient analogue to modern climate change.
• 53 Ma First Whales Return to the sea Pakicetus and relatives begin transitioning from land to aquatic life.
• 33.9 Ma – 33.7 Ma Antarctic Ice Sheet Forms Eocene-Oligocene transition Drake Passage opens; cold circumpolar current drives Antarctic glaciation.
• 6 Ma – 4 Ma First Hominids Apes walk upright Early hominins appear in Africa; bipedal locomotion evolves.
• 3 Ma – 2.8 Ma Panama Land Bridge Closes Atlantic and Pacific separate Central American seaway closes; alters ocean circulation and intensifies glaciation.
• 2.58 Ma – 0.012 Ma Pleistocene Ice Ages Repeated glacial cycles Glacials and interglacials driven by Milankovitch cycles; ice sheets cover North America and Europe.
• 0.3 Ma – present Homo sapiens Modern humans evolve Anatomically modern Homo sapiens appears in Africa, eventually spreading to every continent.