The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism (Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs.

citation

Wikipedia contributors. (2024, March 5). Paleocene. In Wikipedia, The Free Encyclopedia. Retrieved March 12, 2024, from https://en.wikipedia.org/w/index.php?title=Paleocene&oldid=1211962279

I deem him one of the greatest beings alive in our time… We shall never see his like again. His name will live in history. It will live in the annals of war… It will live in the legends of Arabia. Winston Churchill about T.E. Lawrence

Paleocene (Wikipedia) The Paleocene, (IPA: /ˈpæli.əsiːn, -i.oʊ-, ˈpeɪli-/ PAL-ee-ə-seen, -⁠ee-oh-, PAY-lee-) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek παλαιός palaiós meaning “old” and the Eocene Epoch (which succeeds the Paleocene), translating to “the old part of the Eocene”.