The Cenozoic Era spans some 65 million years, beginning 65 million years ago with the Palaeocene epoch.

The Cenozoic Era is divided into the Palaeogene period (which consists of the Palaeocene, Eocene and Oligocene epochs), the Neogene period (which consists of the Miocene and Pliocene epochs) and the Quaternary period (the Pleistocene and Holocene epochs).

The Palaeogene and Neogene periods are collectively termed the Tertiary.

Period Epoch



Holocene is the name given to the period of geological time since the end of the last Ice Age 10,000 years ago. 10,000 years


The Pleistocene epoch begins 1.8 million years ago and concludes with the end of the Ice Ages.

The Pleistocene epoch is dominated by the Ice Ages when extensive ice sheets spread towards the equator from both the Antarctic and Arctic regions covering much of Europe and North America. The last of these ice sheets disappeared about 10,000 years ago.

This period also witnesses the widespread extinction of many species of mammals, particularly giant forms.
Few individual living species of mammals can be traced back to the early part of the Pleistocene epoch, although most modern families of mammal can be traced back to the Miocene epoch.

Sabre-toothed cats, cave lions, cave bears, giant deer, woolly rhinoceroses, and woolly mammoths, which reached a height of 3.7 metres (12 feet) at the shoulder, all roamed during the Pleistocene epoch. All of these animals are now long extinct.

Giant deer.

Giant deer

Woolly mammoth.

Woolly mammoth

1.8 Million years



The Pliocene epoch begins 5 million years ago and spans 3.2 million years, and is the second and final epoch of the Neogene period.

During the Pliocene epoch the Bovids (cattle, sheep, goats, antelope and gazelle) begin to rise to dominate the mammal fauna. There are also reductions in the numbers of horses, rhinoceroses, elephants, tapirs, peccaries and camels. Rodents, including ground-squirrels and beavers, are abundant.

Typical mammals of the Pliocene epoch include Deinotherium, a specialized elephant which reached a height of 3 metres (10 feet) at the shoulder, the giant ground sloth Megatherium which reached a length of 6 metres (20 feet), and the long-legged long-necked Macrauchenia which is a member of an extinct group of mammals called the Litopterns.

The carnivores of this time include sabre-toothed cats, dogs, weasels and stoats.

An important element in the mammal fauna of this time was the rise of the higher Primates, including early man.

Most types of Pliocene marine invertebrates are still living today, and in fresh water environments a radiation and diversification of molluscs and fishes occurred.

The land plants of this period were generally similar to those of today.







5 Million years


The Miocene epoch begins 25 million years ago, and is the first epoch of the Neogene period. It is also the longest epoch of the Cenozoic Era, spanning 20 million years.

The mammals of the Miocene epoch had an essentially modern appearance.
Mammal diversity reached its peak during this period, and many of the earlier primitive mammal families had become extinct. The first deer and giraffes appear, along with the first hyenas.

The dominant hunters of this time were the sabre-toothed cats.

In the seas whales proliferated, and dugongs were numerous. Giant sharks such as Carcharocles megalodon (sometimes called 'Carcharodon') reached an estimated length of 13 metres (42 feet).
Corals, Gastropods and Echinoids were all plentiful.

Sabre-toothed cat.

Sabre-toothed cat



25 Million years



The Oligocene epoch begins 38 million years ago and spans 13 million years. It is the third and final epoch of the Palaeogene period.

Among the mammals dogs, cats, rhinoceroses, pigs and peccaries all became prominent during the Oligocene epoch.
Horses flourished in North America. Gigantic Brontotheres roamed in Asia and North America, along with "giant pigs" such as Archaeotherium which reached a height of 1 metre (3 feet) at the shoulder.
Camels began to become established, and ground sloths and armadillos made their appearance.

Ants and termites appeared among the insects.





38 Million years


The Eocene epoch begins 38 million years ago and spans 17 million years.

During the Eocene epoch mammals continue to radiate into many new forms.
Rodents become the dominant small mammal. Small horses, such as Hyracotherium, are common. Early rhinoceroses and elephants appear, and the massive Uintatherium, which reached a length of 3 metres (10 feet), flourished.

The birds of this period include geese, ducks, herons, owls and hawks.

Insects become important for the pollination of flowering plants, or Angiosperms.

In the seas hexacorals, Bivalves and Gastropods are abundant. Crabs take on a modern form, and fishes were also like living forms. Marine mammals such as whales make their first appearance.





55 Million years


The Palaeocene epoch begins 65 million years ago and spans 10 million years. It is the first epoch of the Cenozoic Era (and also the first epoch of the Palaeogene period) and marks the beginning of the "Age of the Mammals".

Dinosaurs and many other groups of reptiles from the earlier Cretaceous period are now all extinct.

On land the mammals which survived from the Cretaceous period begin to expand rapidly.
There are also large flightless birds, such as Diatryma.

In the seas the Bivalves and Gastropods replace the now extinct Ammonites as the dominant molluscs. Sharks and teleost fishes are abundant.

Flowering plants, or Angiosperms, become widespread.



65 Million years

Cenozoic. Mesozoic. Palaeozoic.


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