Introduction to Cenozoic Era
Cenozoic means “The Recent Life”. This era includes the last 65 million years of the Earth’s history. It is generally known as the “Age of Mammals” but with equal justice could be called the “Age of birds”, “Age of Insects” or “Age of Flowering Plants”. The plants and animal life in that period were mostly like today on Earth.
This era is marked by the evolution of these living organisms to today’s modern life. Striking climate changes took place. Polar regions cooled and the general warm temperature climate gave way to a wider climatic range.
The continents were similar to those of today. Although there was mountain building, continental warping, and volcanic activity.
Periods and Epochs of Cenozoic Era
The Cenozoic era is divided into two periods: the Tertiary and the Quaternary.
The Tertiary Period
The tertiary period lasted for 62 million years and is subdivided into five epochs named from earliest to latest, Paleocene, Eocene, Oligocene, Miocene, and Pliocene. This period is studied in more detail than any other because its flora and fauna had a great resemblance to the living forms of today.
Plant life
During this period, all the plant life had evolved and angiosperms attained widespread dominance.
Animal life
The tertiary period witnessed the great rise of mammals and birds. The mammals occupied all the niches which were once dominated by dinosaurs. The Creodonts were the dominant carnivores, for instance, Oxyaena.
Paleocene Epoch
The climatic condition was warmer and uniform than today. many new mammals evolved. The first armadillos, primitive carnivores, primates, and ancestors of today’s mammal life appeared.
Although dinosaurs were wiped out but reptiles like crocodiles, snakes, lizards persisted.
Eocene epoch
The climate was dry and seasonal. In the Eocene epoch, horses, pigs, elephants, peccaries appeared for the first time. The aquatic Cretacean appeared in the middle of this epoch. These included porpoises and whales. Most of the modern birds appeared during the Eocene epoch.
Oligocene epoch
Antarctica was covered with ice for the first time and lowered the sea level. In the Oligocene epoch, deer, cattle, and other antelopes appeared for the first time.
Miocene epoch
New mountain ranges formed during this epoch. The first half was warmer but new mountains formation changed oceanic currents thus changing rain patterns increased the cool temperatures. Seals and sea lions appeared for the first time in Miocene.
Pliocene Epoch
The continents were the same as today. The first half was warmer but in the last half climate changes occurred and the temperature dropped down. Most flora and fauna were like today’s but there was a difference in individual species.
The Quaternary Period
The Quaternary period which lasted for the last two and a half million years also called the “Age of Man” is subdivided into two epochs named Pleistocene and the Recent.
The Pleistocene
The Pleistocene was marked by the four periods of heavy glaciation, between which sheets of ice retreated. The last glaciation retreated about 11, 000 years ago.
The marine fauna of the Pleistocene epoch shows little difference from the fauna of today. The terrestrial fauna of the Pleistocene epoch included mammoths, mastodons, and wooly rhinoceroses in cold climates.
Elephants, camels, and deer existed in warmer climates.
One of the greatest extinctions of mammalian life took place during the Pleistocene when species such as Irish Elks, Mammoths, wooly rhinoceroses, toothed tigers, mastodons, deer, large ground sloths, glyptodonts, and wolves vanished from the Earth.
Emerging in the late Pleistocene, Homo sapiens were first represented by Neanderthal man who appeared about 0.1 million years ago. His successor, Cro – Magnon man appeared about 50, 000 years ago.