During the Paleocene epoch, which lasted from approximately 66 to 56 million years ago, the Earth experienced a significant shift in climate and vegetation. The Paleocene was marked by a global warming event known as the Paleocene-Eocene Thermal Maximum, which caused a rapid increase in temperature and a shift towards more humid conditions. 

One of the most notable changes in plant life during this time was the rise of angiosperms, or flowering plants. While angiosperms had existed prior to the Paleocene, they underwent a significant diversification during this epoch and became much more dominant in many ecosystems. This is evidenced by the abundance of fossilized angiosperm pollen and leaves found in Paleocene sediments. 

In addition to angiosperms, other types of plants also thrived during the Paleocene. Gymnosperms, which include conifers and cycads, were still present but became less dominant than they had been in previous epochs. Ferns and other spore-bearing plants also continued to exist, although they too became less common over time.