Paleocene

The Paleocene epoch (65-56 MYA) ("early dawn of the recent") is the first geologic epoch of the Palaeogene period in the modern Cenozoic era. As with most other older geologic periods, the strata that define the epoch's beginning and end are well identified, but the exact date of the end is uncertain.

Related Topics:
Epoch - MYA - Palaeogene - Cenozoic - Era - Geologic periods - Strata

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The Paleocene epoch immediately followed the mass extinction event at the end of the Cretaceous, known as the K-T boundary (Cretaceous - Tertiary), which marks the demise of the dinosaurs. The die-off of the dinosaurs left unfilled ecological niches worldwide, and the name "Paleocene" refers to the "old(er) – new" fauna that arose during the epoch, prior to the emergence of modern mammalian orders in the Eocene.

Related Topics:
Extinction event - Cretaceous - K-T boundary - Dinosaurs - Fauna - Mammalian - Orders - Eocene

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The K-T boundary that marks the separation between Cretaceous and Paleocene is visible in the geological record of much of the Earth by a discontinuity in the fossil fauna, with high iridium levels. There is also fossil evidence of abrupt changes in flora and fauna. There is some evidence that a substantial but very short-lived climatic change may have occurred in the very early decades of the Paleocene. There are a number of theories about the cause of the K-T extinction event, with most evidence supporting the impact of a 10 km diameter asteroid near Yucatan, Mexico.

Related Topics:
Iridium - Flora - Fauna - Extinction event - Diameter - Asteroid - Yucatan - Mexico

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The end of the Paleocene (55.5/54.8 Ma) was marked by one of the most significant periods of global change during the Cenozoic, a sudden global change, the Paleocene-Eocene Thermal Maximum, which upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and on land, a major turnover in mammals.

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