The K-T Extinction Event marked the end of the Mesozoic and began the Cenozoic Era.[1][2] This geological era began 66 million years ago and continues to the present day. The Cenozoic is also known as the Age of Mammals because of the large mammals that have dominated it.


  1. "Cenozoic". Unabridged. Random House. 
  2. "Cenozoic". Merriam-Webster Dictionary.