page_title: Paleocene
section_title: Flora
hierarchical_section_title: Paleocene / Flora
caption_attribution_description: English: Ancient landscape across the Cretaceous/Paleogene time interval in central Patagonia. Main floristic types from the Danian: Podocarps, Cheirolepidiaceae, palms. doi:10.1371/journal.pone.0052455.g007
context_page_description: The Paleocene, or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago. It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek palæo- meaning "old" and the Eocene Epoch, translating to "the old part of the Eocene".
  The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene thermal maximum, which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification.
  In the Paleocene, the continents of the Northern Hemisphere were still connected via some land bridges; and South America, Antarctica, and Australia had not completely separated yet.
context_section_description: The warm, wet climate supported tropical and subtropical forests worldwide, mainly populated by conifers and broad-leafed trees. In Patagonia, the landscape supported tropical rainforests, cloud rainforests, mangrove forests, swamp forests, savannas, and sclerophyllous forests. In the Colombian Cerrejón Formation, fossil flora belong to the same families as modern day flora—such as palm trees, legumes, aroids, and malvales—and the same is true in the North Dakotan Almont/Beicegel Creek—such as Ochnaceae, Cyclocarya, and Ginkgo cranei—indicating the same floral families have characterized South American rainforests and the American Western Interior since the Paleocene.
  The extinction of large herbivorous dinosaurs may have allowed the forests to grow quite dense, and there is little evidence of wide open plains. Plants evolved several techniques to cope with high plant density, such as buttressing to better absorb nutrients and compete with other plants, increased height to reach sunlight, larger diaspore in seeds to provide added nutrition on the dark forest floor, and epiphytism where a plant grows on another plant in response to less space on the forest floor. Despite increasing density—which could act as fuel—wildfires decreased in frequency from the Cretaceous to the early Eocene as the atmospheric oxygen levels decreased to modern day levels, though they may have been more intense.
caption: Restoration of a Patagonian landscape during the Danian
exif: {}