The Cenozoic era meaning “new life”. This era includes last 65 million years of earth history. Current era on this plant earth is Cenozoic era.
Geologically, the Cenozoic is the era when continents moved into their current positions. Australia-New Guinea, having split from Gondwana during early Cretaceous, drifted north and eventually, collided with South-East Asia. Antarctica moved into its current position over the South Pole; the Atlantic ocean widened and, later in the era, south america became attached to north america. India Collided with Asia between 55 and 45 million years ago; Arabia collided with eurasia, closing the Tethys ocean, around 35 million years ago.
The Cenzoic era has been a period of long-term cooling. Slow but striking change in climate took place in this time. Polar regions cooled and the general warm temperature climate gave way to a wider climatic range. The continents were similar to those today, although there was mountains buildings, continental wrapping and volcanic activity.
Though generally referred to as the: Age of mammals, this period with equal justice, could be called as the Age of birds, Age of insects, Age of flowering plants, Grass also played a very important role in this era, shaping the evolution of birds and mammals to fed on it. One group that diversified significantly in the Cenozoic were the snakes and they evolved into a huge amount of forms, following the evolution of their current primary prey source, the rodents.
Cenozoic era is subdivided into two periods”
This period lasted about 62 million years. Tertiary period has been studied in greater detail than any other period, partly because, Its flora and fauna bear close similarities to the living forms of today. But mainly, in search of petroleum, of which more than 50% of our production comes from tertiary rocks. All modern groups of plants had evolved and angiosperms, among them, attained widespread dominance.
This period includes the last 2 or 2.5 million years of earth history. It is also known as Age of Man.
Subdivisions of Tertiary period
Tertiary period is subdivided into five epochs:
“Paleocene” comes from Greek and refers to the “old”. Paleocene is a geological epoch that began about 65 Ma (Million years ago) and lasted for about 11 Ma. It is the first epoch of the Tertiary period in the modern Cenozoic era. Explosive radiations of Flowering Plants and spread of Primitive Mammals in this epoch.
The name of Eocene comes from Greek (eos, “dawn”) and (Kainos, “new”) and refers to the “dawn” of modern (new) mammalian fauna that appeared during the epoch. The Eocene epoch, began about 54 Ma and lasted for about 16 Ma. The start of the Eocene is marked by the emergence of the first modern mammals (hoofed and carnivores established).
The name of Oligocene comes from the Greek (oligos, “few”) and (Kainos, “new”) and referred to the sparsity of additional modern mammalian faunas after a burst of evolution during Eocene. The Oligocene is a 3rdgeologic epoch of Tertiary period, began about 38 Ma and lasted for about 12 Ma. Maximum spread of forests and rise of flowering plants in this epoch.
The name of Miocene comes from the Greek (meiōn, “less”) and (Kainos, “new”) and means less recent. The Miocene is a geological epoch began about 26 Ma and lasted for about 19 Ma. The plants and animals of the Miocene were fairly modern. Mammals and birds were well established. There was great expansion of the grass land in this epoch.
The name of Pliocene comes from the Greek (pleion, “more”) and (Kainos, “new”) and means roughly “continuation of the recent”. The Pliocene epoch began about 7 Ma and lasted about 5 Ma. Decline of forests, spread of grasslands continued, flowering plants developed. Man evolved from man like apes, mammals, birds and insects were dominant.
The tertiary saw the rise of mammals and birds. Creodonts, dominant carnivores of early tertiary period. Elephants, horses, pigs and peccaries first make their appearance in Eocene. Aquatic carnivore cetaceans such as Porposies appeared in middle Eocene. Deers, cattles and antelopes appear in oligocene. Whales, seals and sea lions appear in miocene.
Quaternary period is also called as the Age of Man. It includes about the final 2 to 2.5 million years of earth history. The Quaternary period is the youngest periods of the Cenozoic era in geologic time scale.
Subdivisions of Quaternary period
It is usually divided into two epochs:
This is the first epoch of Quaternary period or 6thepoch of the Cenozoic era. The Pleistocene is the epoch begins about 2 million years covering world’s recent period of repeated glaciations. Great extinction of species in this epoch e.g., mammals. The Pleistocene is marked by four periods of heavy glaciations. Continental ice sheets up to 3000 meters thick spread over much of their hemisphere. The last glaciation retreated about 11000 years ago.
The Holocene is the part of Quaternary periods. Its name comes from the Greek word (holos, “whole or entire”) and (kainos, “new”), meaning “entirely recent”. It has been identified with the current warm period. The Holocene is a geological epoch which began approximately 11700 years ago. According to traditional geological thinking, the Holocene continues to the present. This Holocene epoch is also called as Age of Man.
Fauna of Quaternary period
Mammoths, mastodons, and wooly rhinoceroses in cold climate. While horses, camels and deers in warmer climate.
Extinct species of Cenozoic era
Species that extinct in Pleistocene period are as follows: Irish Elk, Wooly mammoths, wooly rhinoceroses, sabre toothed tigers, Mastodons, Giant deers, Large ground sloths, Glyptodonts and wolves. This reason for the wide extermination is not definitely known. Emerging in the late Pleistocene, Homo sapiens was first represented by the Neanderthal man, who appeared about 0.1 million year ago.