Smithsonian National Museum of Natural History Geologic Time The Story of a Changing Earth
Presented by the Department of Paleobiology.
The Paleocene
Epoch Overview
Terrestrial Life through the Paleocene
Life in the Paleocene Oceans
Climates and Shifting Continents
Lower jaw of Plesiadapis cookei
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Shark's tooth
Ptilodus montanus
Ectocion ralstonensis
Caenolambda pattersoni
Japanese scholar tree
Sycamore relative and dawn redwood
Insect damage on plant leaves
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Foundational Concepts
Dating Methods
Earth Processes
Life Processes
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Paleocene 65.5–55.8 mya
Defining Characteristics:
  • • “Age of Mammals” begins
  • • flowering plants and conifers abundant
Secondary Characteristics:
  • • global climate warming
  • • abundant plants, fish, crocodiles, and mammals

On the basis of fossil plants, W. P. Schimper separated the lower part of Lyell's Eocene and named it Paleocene in 1874. The name is derived from the Greek words palaios, meaning “ancient” or “old,” and kainos, meaning “recent.” Schimper chose this name to describe the oldest epoch of the “recent” Paleogene Period, marking the onset of the Cenozoic Era. Paleocene rocks are common in the western United States, South America, western Europe, and eastern Asia.

At the onset of the Paleocene Epoch, Earth was recovering from the end-Cretaceous asteroid impact. The climate was subtropical almost to the polar circles, ocean temperatures were high, and polar ice caps were absent. The oceans invaded many coastal plain areas, as well as some continental interiors, but mountain-building forced these seas to retreat. Land bridges existed between North America, Asia, and Europe, while South America and Antarctica remained connected to each other. Africa, Australia, and India were island continents or subcontinents. Mammals began to take advantage of the niches left empty by the extinction of the dinosaurs, evolving into many new species. Abrupt warming at the end of the Paleocene followed the release of a large volume of methane contained in seafloor sediments. This led to a major extinction of deep-sea foraminiferans and a major reorganization of many terrestrial and marine communities.


Epoch Overview | Terrestrial Life through the Paleocene | Life in the Paleocene Oceans
Climates and Shifting Continents

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