The event marks the end of the Mesozoic Era and the beginning of the Cenozoic Era.

However, since the Azolla event of 49 mya, the Cenozoic Era has been a period of long-term cooling.

The Eocene ( symbol E < sub > O </ sub >) epoch, lasting from about 56 to 34 million years ago ( to ), is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era.

About 50 to 55 million years ago, in the Eocene Epoch of the Cenozoic Era, the plate collided with Asia after covering a distance of, having moved faster than any other known plate.

Following the Paleozoic, the Mesozoic extended roughly 180 million years: from 251 million years ago ( Mya ) to when the Cenozoic Era began 65 Mya.

The second period in the Cenozoic Era, it follows the Paleogene Period and is succeeded by the Quaternary Period.

By dividing the Cenozoic Era into three ( arguably two ) periods ( Paleogene, Neogene, Quaternary ) instead of 7 epochs, the periods are more closely comparable to the duration of periods in the Mesozoic and Paleozoic eras.

Following formal discussions at the International Geological Congress, Oslo Norway, August 2008, the International Commission on Stratigraphy ( ICS ) decided in May 2009 to make the Quaternary the youngest period of the Cenozoic Era with its base at 2. 588 Mya and including the Gelasian age, which was formerly considered part of the Neogene Period and Pliocene Epoch.

The Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era .< ref name =" Gibbard ">

The Paleogene ( alternatively British English Palaeogene or Palæogene, informally Lower Tertiary ) is a geologic period and system that began 65. 5 ± 0. 3 and ended 23. 03 ± 0. 05 million years ago and comprises the first part of the Cenozoic Era.

The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS.

In 2009, it was decided to make the Quaternary the youngest period of the Cenozoic Era with its base at 2. 588 Mya and including the Gelasian stage, which was formerly considered part of the Neogene Period and Pliocene Epoch.

The period began with the demise of the non-avian dinosaurs in the Cretaceous – Paleogene extinction event, at the start of the Cenozoic Era, spanning to the beginning of the most recent ice age at the end of the Pliocene Epoch.

The Tertiary is no longer recognized as a formal unit by the International Commission on Stratigraphy, its traditional span being divided between the Paleogene and Neogene Periods of the Cenozoic Era.

This is, geologically-speaking, rather a young group, having evolved from the Late Paleocene in the Cenozoic Era.

During the Cenozoic Era, volcanic activity and extensive lava flows in the region dramatically changed the landscape.

Geomagnetic polarity during the late Cenozoic Era.

It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed.

During the Cenozoic Era the chalk was uplifted ( see Cenozoic Era ).

The Cenozoic is divided into three periods: The Paleogene, Neogene, and Quaternary ; and seven epochs: The Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene.

* 65 Ma: Cretaceous – Paleogene extinction – Dinosaurs die ; end of Mesozoic and beginning of Cenozoic

The Hadean eon represents the time before fossil record of life on Earth ; its upper boundary is now regarded as 4. 0 Ga. Other subdivisions reflect the evolution of life ; the Archean and Proterozoic are both eons, the Palaeozoic, Mesozoic and Cenozoic are eras of the Phanerozoic eon.

The egg-laying monotremes are known from fossils of the Cretaceous and Cenozoic periods ; they are represented today by the platypus and several species of echidna.

The cliffs come from the earlier Cenozoic Afton basalt flow ; the magma that caused the maar explosion was also basalt.

Megalodon ( ; meaning " big tooth ", from Greek μέγας ( mega, " big ") and ὀδούς ( odon, " tooth ")) is an extinct species of shark that lived approximately 28 to 1. 5 million years ago, during the Cenozoic Era ( late Oligocene to early Pleistocene ).

The global climate of the Eocene was probably the most homogeneous of the Cenozoic ; the temperature gradient from the equator to the poles was half that of today's, and the deep ocean currents were exceptionally warm.

It is dominated by Cenozoic sedimentary rocks, probably originating from the Australian continent ; Also present are younger volcanic rocks and more recent alluvial deposits.

Bolshoy Lyakhovsky Island consists of highly folded and faulted Precambrian metamorphic rocks and turbidites ; Mesozoic turbidites and igneous rocks ; and Cenozoic sediments.

After 150 million years of volcanism, plutonism, metamorphism, and thrust faulting had run their course, the early part of the Cenozoic era ( early Tertiary, 65 – 30 Ma ) was a time of repose ; neither igneous nor sedimentary rocks of this age are known here.

; Cenozoic

The Cenozoic is also known as the Age of Mammals, because the extinction of many groups allowed mammals to greatly diversify.

The first mammals also appeared during the Mesozoic, but would remain small and modest until the Cenozoic.

Many groups of synapsids such as anomodontians and therocephalians that once comprised the dominant terrestrial fauna of the Permian also became extinct during this time, but during the Triassic, one group ( Cynodontia ) gave rise to the descendant taxon Mammalia, which survived through the Mesozoic to later diversify during the Cenozoic.

The geologic make-up of Rocky Mountain National Park was also affected by deformation and erosion during the Cenozoic Era.

This also accords with recent revisions of the fossil record in New Zealand that reveal no examples of Agathis or Wollemia-like remains older than the Cenozoic.

The Alpine orogeny ( sometimes also called Alpide orogeny ) is an orogenic phase in the Late Mesozoic ( Eoalpine ) and Cenozoic that formed the mountain ranges of the Alpide belt.

As honorary director of the Cenozoic Research Laboratory he also studied fossils of the Peking Man, then known as Sinanthropus pekinensis, unearthed at Zhoukoudian, China.

It is one of three geologic eras of the Phanerozoic Eon, preceded by the Paleozoic (" ancient life ") and succeeded by the Cenozoic (" new life ").

Being the first institution of its kind, the Cenozoic Laboratory opened up new avenues for the study of paleogeology and paleontology in China.

Like its predecessor, Walking with Dinosaurs, it recreates life in the Cenozoic by using a combination of both computer-generated imagery and animatronics.

Phorusrhacids (" Wrinkle-bearers ", in reference to the wrinkled surface of the jaw of Phorusrhacos ), colloquially known as " terror birds " as the larger species were apex predators during the Miocene, were a clade of large carnivorous flightless birds that were the dominant predators in South America during the Cenozoic, 62 – 2 million years ( Ma ) ago.