The Cenozoic Era began about 66 million years ago and continues up to the present day.

Basic timeline

  • The Cenozoic starts right after the mass extinction that wiped out the non‑avian dinosaurs, around 66–65.5 million years ago.
  • It has not ended yet; we are currently living in the Cenozoic Era.

Main subdivisions

Geologists usually divide the Cenozoic into three major periods.

  • Paleogene: about 66–23 million years ago.
  • Neogene: about 23–2.6 million years ago.
  • Quaternary: about 2.6 million years ago to today.

Why it matters

  • The Cenozoic is often called the “Age of mammals” because mammals diversified and became dominant after the dinosaur extinction.
  • Modern continents, climates, and many familiar groups of plants and animals (including humans) took shape during this era.

TL;DR: The Cenozoic Era runs from roughly 66 million years ago right up to now, and it’s the era in which modern Earth and mammals (including humans) rose to prominence.