1)TERTIARY PERIODPALAEOCENE AND EOCENE EPOCHSNo large land animals existed at the start of the Palaeocene, however the land was soon repopulated by large mammals that had developed from small survivors of the KT extinction. Bats, rodents, owls, herons and eagles made their first appearance while crocodiles, turtles and frogs thrived in the tropical Eocene world. Snakes evolved rapidly as there was now an abundant food supply with the new rodents that had evolved.
Modern forms of marine life became firmly established. Molluscs, barnacles and crustaceans evolved taking on now familiar forms. The first species of penguins appeared and inhabited the southern seas while the first whales and sea cows evolved. During this period of time, the land was dominated by tropical forests. Towards the end of the Eocene the world cooled. As a result, deciduous and coniferous trees became dominant at higher altitudes and tropical forests retreated to the equatorial regions. PLIOCENE EPOCHThe first humans evolved from chimp-like ancestors. Hoofed animals such as horses, camels, elephants and antelopes became more diverse as they took advantage of the newly developing grasslands, while large sabre-toothed cats hunted the plains and forests for their prey.
Sperm whales, humpbacks, killer whales and many modern forms of dolphins were now all present in the oceans. Numerous fish and other aquatic animal species unique to the Caribbean Sean evolved. Conditions became drier and cooler throughout this period which allowed the grasslands to continue to spread. Tropical plants started to disappear from high latitudes. Fruit and willow trees thrived in the valleys of the northern hemisphere. HOLOCENE EPOCHThe Holocene has been dominated by humans. With their species multiplying like no other previously, they have been able to spread out across Earth to the most isolated places on the planet. As a result of Human success, there has been a great decline in the diversity of life on Earth. Humans have destroyed the habitats of other species to house and feed their growing populations. They have hunted creatures to extinction and created pollution that threatens animal and plant life worldwide.
Just like on the land, the seas have also been devastated by human intervention. Some species of seals and sea cows have been hunted to extinction, while whaling between 1850 - 1950 almost wiped out many whale species. Industrial scale fishing has changed the balance of life in oceans while rivers and water ways are used as dumping grounds for sewage, waste and chemicals. Forests on land have been cleared to make way for agriculture and farming. They have introduced different plant species into habitats causing native vegetation to be wiped out. |
This Era is broken up into two main periods, the Tertiary and Quaternary Periods and then again into many smaller time Periods:
1) Tertiary Period - Palaeocene and Eocene Epochs (65 - 33.7 MYA) Mammals such as horses, bats and whales evolve to dominate. Early carnivores evolve. - Oligocene and Miocene Epochs (33.7 - 5.3 MYA) Creodonts evolve and modern mammals become dominant. By the end of this period, most mammals and birds have evolved. - Pliocene Epoch (5.3 - 1.75 MYA) Hominids, the ape-like ancestors of humans evolve. Early sabre-tooths evolve. 2) Quaternary Period - Pleistocene Epoch (1.75 - 0.01 MYA) The 'Great Ice Age' takes place. Neanderthals and Homo Sapiens (humans) evolve. The sabre toothed tiger, mastodons and mammoths evolve. - Holocene Epoch (0.01 - now) The last ice age ends. Human civilisation develops OLIGOCENE AND MIOCENE EPOCHSIt is during this time that many modern animals essentially evolved. Monkeys and apes replaced primitive primates and while the grasses spread across the plains, many grazing mammals including horses, elephants and camels evolved to resemble todays animals. Modern forms of carnivores, birds, lizards and snakes also rose.
By the Miocene, familiar fish species such as mackerels and flatfish had evolved. The ocean was now home to a new top predator, the great white shark while carp, catfish and other fresh water fish species evolved. Modern whales and the first seal species developed in the Oligocene. On land tropical forests slowly reduced and made way for drier grasslands. Broad leaved deciduous trees spread across the continents. The evolution of grasses meant they could survive with a little amount of water and as a result vast savannah and prairie environments became more dominant. 2) QUATERNARY PERIODPLEISTOCENE EPOCHTemperatures dropped in the northern hemisphere during the Pleistocene and as a result animals adapted to warmer climates. In the colder climates, a number of large fur-covered animals took their place. Among these new animals were mammoths, large rhinos, cave lions and giant deer. New human species emerged and began to have a great effect on the diversity of these large mammals.
There was little or no change to marine life throughout this period. However, corals and reefs were affected by the falling sea levels. Grasslands continued to develop and a new kind of coniferous forest the Taiga emerged. Tropical forests continued to retreat as temperatures dropped and became drier. Climate change at the end of this period destroyed some of these developing plants and forests. |