Cenozoic

	Email		Print
	Bookmark		Link

Cenozoic

The Cenozoic (also Cænozoic or Cainozoic) Era

Era

An era is a commonly used word for long period of time. When used in science, for example geology, eras denote clearly defined periods of time of arbitrary but well defined length, such as for example the Mesozoic era from 252 Ma?66 Ma, delimited by a start event and an end event....
(meaning "new life" (Greek

Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
(kainos), "new", and (zoe), "life"), is the most recent of the three classic geological eras and covers the period from 65.5 million years ago to the present. It is marked by the Cretaceous–Tertiary extinction event at the end of the Cretaceous

Cretaceous

The Cretaceous , usually abbreviated K for its German translation Kreide, is a geologic period from circa to million years ago . In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period....
that saw the demise of the last non-avian dinosaur

Dinosaur

Dinosaurs were the dominant vertebrate animals of Landform ecosystems for over 160 million years, from the late Triassic Period until the end of the Cretaceous Period , when most of them became extinct in the Cretaceous?Tertiary extinction event....
s and the end of the Mesozoic

Mesozoic

The Mesozoic Era is one of three Geologic time scale of the Phanerozoic eon . The division of time into eras dates back to Giovanni Arduino, in the 18th century, although his original name for the era now called the 'Mesozoic' was 'Secondary' ....
Era.

Discussion

Ask a question about 'Cenozoic'

Start a new discussion about 'Cenozoic'

Answer questions from other users

Full Discussion Forum

Encyclopedia

The Cenozoic (also Cænozoic or Cainozoic) Era

Era

Greek language

Cretaceous

Dinosaur

Mesozoic

Subdivision

The Cenozoic Era is divided into two periods, the Paleogene

Paleogene

The Paleogene is a geologic period that began 65.5 ? 0.3 and ended 23.03 ? 0.05 million years ago and comprises the first part of the Cenozoic era....
and Neogene

Neogene

The Neogene is a Geologic time scale#Terminology starting 23.03 ? 0.05 million years ago and lasting either until today or ending 2.588 million years ago with the beginning of the Quaternary....
, and they are in turn divided into epoch

Epoch

Periodization* Epoch - A defining moment in the beginning of, or characteristic of, a distinctive historical period or era.* On the geologic time scale, a span of time smaller than a "period" and larger than an "age"....
s. The Paleogene consists of the Paleocene

Paleocene

The Paleocene or Palaeocene, "early dawn of the recent" is a geologic epoch that lasted from 65.5 ? 0.3 Mega-annum to 55.8 ? 0.2 Ma . It is the first epoch of the Palaeogene Period in the modern Cenozoic era ....
, Eocene

Eocene

The Eocene Geologic time scale is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era....
, and Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Geologic Timescale and extends from about 33.9 million to 23 million years before the present....
epochs, and the Neogene consists of the Miocene

Miocene

The Miocene is a Geologic time scale of the Neogene period and extends from about 23.03 to 5.33 million years before the present. As with other older geologic periods, the rock beds that define the start and end are well identified but the exact dates of the start and end of the period are uncertain....
, Pliocene

Pliocene

The Pliocene epoch is the period in the geologic timescale that extends from 5.332 million to 1.806 million years before present.The Pliocene is the second epoch of the Neogene period in the Cenozoic era....
, Pleistocene

Pleistocene

The Pleistocene is the epoch from 1.8 million to 10,000 years Before Present covering the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, and Holocene

Holocene

The Holocene is a geological Epoch which began approximately 11,700 years ago . According to traditional geological thinking, the Holocene continues to the present....
epochs, the last of which is ongoing. Historically, the Cenozoic has been divided into periods (or sub-eras) named the Tertiary

Tertiary

The Tertiary is a a term for a Geologic time scale#Terminology 65 million to 1.8 million years ago. The Tertiary covered the time span between the superseded Secondary period and an out-of-date definition of the Neogene#Controversy....
(Paleocene through Pliocene) and Quaternary

Quaternary

The Quaternary Period is the Geologic Time Scale period after the Neogene Period, spanning 1.805 +/- 0.005 million years ago to the present. The Quaternary includes two geologic epochs: the Pleistocene and the Holocene epoch ....
(Pleistocene and Holocene). It is known as the age of mammals.

Tectonics

Geologically

Geology

Geology is the science and study of the solid and liquid matter that constitute the Earth. The field of geology encompasses the study of the composition, structural geology, physical properties, dynamics, and History of the Earth of Earth materials, and the processes by which they are formed, moved, and changed....
, the Cenozoic is the era when the continent

Continent

A continent is one of several large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents ? they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia ....
s moved into their current positions. Australia-New Guinea

Australia (continent)

Australia Sahul is the smallest of the geographic continents, though not of geological continents. There is no universally accepted definition of the word "continent"; the lay definition is "One of the main continuous bodies of land on the earth's surface." ....
split from Gondwana

Gondwana

Gondwana , originally Gondwanaland is the name given to a southern precursor-supercontinent and then as a remnant separated from Laurasia 180- during the breakup of the Pangaea supercontinent that existed about 500 to 200 Annum ago into two large segments. and drifted north and, eventually, adjacent to South-east Asia; Antarctica

Antarctica

Antarctica is Earth's southernmost continent, overlying the South Pole. It is situated in the Antarctica of the southern hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean....
moved into its current position over the South Pole

South Pole

The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's rotation intersects the surface....
; the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions; with a total area of about 106.4 million square kilometres . It covers approximately one-fifth of the Earth's surface....
widened and, later in the era, South America

South America

South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere....
became attached to North America

North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
.

India collided with Asia between 55 and 45 million years ago; Arabia collided with Eurasia, closing the Tethys ocean

Tethys Ocean

The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean....
, around .

Climate

The Cenozoic Era has been a period of long-term cooling. In the early Cenozoic, particulate ejecta from the K-T boundary impact blocked incoming solar radiation ^ref?. After the tectonic creation of Drake Passage

Drake Passage

The Drake Passage or Mar de Hoces -Sea of "Hoces"- is the body of water between the southern tip of South America at Cape Horn, Chile and the South Shetland Islands of Antarctica....
, when Australia fully detached from Antarctica during the Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Geologic Timescale and extends from about 33.9 million to 23 million years before the present....
, the climate cooled significantly due to the advent of the Antarctic Circumpolar Current

Antarctic Circumpolar Current

The Antarctic Circumpolar Current is an ocean current that flows from west to east around Antarctica. An alternate name for the ACC is the West Wind Drift....
which brought cool deep Antarctic water to the surface. Warm conditions returned in the Miocene

Miocene

Carbon dioxide

Carbon dioxide is a chemical compound composed of two oxygen atoms covalent bond to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state....
.^ref? When South America became attached to North America creating the Isthmus of Panama

Isthmus of Panama

The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North America and South America....
, the Arctic region cooled due to the strengthening of the Humboldt

Humboldt Current

The Humboldt Current is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru....
and Gulf Stream

Gulf Stream

The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Current, is a powerful, warm, and swift Atlantic Ocean ocean current that originates in the Gulf of Mexico, exits through the Straits of Florida, and follows the eastern coastlines of the United States and Newfoundland and Labrador before crossing the At...
currents^ref?, eventually leading to the Last Glacial Maximum

Last Glacial Maximum

The Last Glacial Maximum refers to the time of maximum extent of the ice sheets during the last glaciation , approximately 20,000 years ago. This extreme persisted for several thousand years....
or the last ice age.

Life

The Cenozoic Era is the age of new life. During the Cenozoic, mammals diverged from a few small, simple, generalized forms into a diverse collection of terrestrial, marine, and flying animals, giving this period its other name, the Age of Mammals. The Cenozoic is just as much the age of savanna

Savanna

A savanna, or savannah, is a tropical, subtropical or temperate woodland ecosystem characterized by the trees being sufficiently small or widely spaced so that the Canopy does not close....
s, or the age of co-dependent flowering plant

Flowering plant

The flowering plants or angiosperms are the most widespread group of Embryophytes. The flowering plants and the gymnosperms are the only extant groups of Spermatophyte....
s and insects. Grass also played a very important role in this epoch, shaping the evolution of the birds and mammals that fed on it. One group that diversified significantly in the Cenozoic as well were the snakes. Evolving in the Cenozic, the snakes evolved into a huge amount of forms, especially colubrids, following the evolution of their current prey source, the rodents.

In the earlier part of the Cenozoic, the world was dominated by the gastornid birds, terrestrial crocodiles like Pristichampsus

Pristichampsus

Pristichampsus is an extinct genus of crocodylian that grew to approximately three metres in length.Pristichampsus was heavily armoured, with long limbs indicating a cursorial lifestyle....
, and a handful of primitive large mammal groups like uintatheres, mesonychid

Mesonychid

Mesonychia are an extinct order of medium to large-sized carnivore mammals that were closely related to artiodactyls , and to cetaceans . A few experts unite Mesonychia with the whales to form the clade "Cete." They first appeared in the Early Paleocene and went into a sharp decline at the end of the Eocene and died out entirely when the la...
s, and pantodonts. But as the forests began to recede and the climate began to cool, other mammals took over. The cenozoic is full of mammals both strange and familiar, including chalicothere

Chalicothere

Chalicotheres were a group of odd-toed ungulate mammals that evolved in the mid Eocene around 40 million years ago from small, forest animals similar to the Hyracotheriums....
s, oreodont

Oreodont

Sometimes called a prehistory "ruminant Hog ," , the typical oreodont was a sheep-sized , cud herbivore with a short face, tusk-like canine teeth, heavy body, long tail, short feet, and even-toed ungulate hoofs....
s, whale

Whale

Whales are marine mammals of order Cetacea which are neither dolphinsmembers, in other words, of the families Oceanic dolphin or River dolphinnor porpoises....
s, primates, entelodont

Entelodont

Entelodonts, sometimes nicknamed Terminator Pigs , are an extinct, omnivorous, group of mammals, distantly related to modern pigs and other non-ruminant artiodactyls....
s, saber-toothed cats, mastodon

Mastodon

Mastodons or Mastodonts are members of the extinction genus Mammut of the order Proboscidea and form the family Mammutidae; they resembled, but were distinct from, the woolly mammoth, which belongs to the family Elephantidae....
s and mammoth

Mammoth

A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of the Elephantidae and close relatives of modern elephants....
s, three-toed horses, giant rhinoceros

Rhinoceros

Rhinoceros , often colloquially abbreviated rhino, is a name used to group five extant species of odd-toed ungulates in the family Rhinocerotidae....
s like Indricotherium, and brontotheres, just to name a few.

Bibliography

British Caenozoic Fossils, 1975, The Natural History Museum, London.
Geologic Time, by Henry Roberts.

Cenozoic

Subdivision

Tectonics

Climate

Life

See also

Bibliography