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Period: to
Oligocene Epoch
The oligocene epoch occured approximately 38 million years ago. -
Early forms of Amphicyonids, canidaes, camels, tayassuidae
Early forms of Amphicyonids (large terrestrial carnivores), canidaes (from the dog family), camels, tayassuidae (pigs), anthracotheres (hippos), and caprimulgiformes (birds that have wide mouths for catching insects) started to appear -
Grasses and composites
Grasses and composites (things made from several parts or elements) started to grow on a global scale. Also humid forests were becoming more common in the southern parts in
South America. -
Apperance of mammals and primates
On land, mammals such as horses, deer, camel, elephants, cats, dogs, and primates began to appear, except in Australia. The
continuation of land mammal migration between Asia and North America was responsible for the distrubution of several new continents. -
Appearance of Cricetids & extinction of Mesothermal Dicotyledons
In North America, the cricetids (voles and hamsters) first appeared while the mesothermal dicotyledons (a group of flowering plants) went extinct. -
The growing in size of unugulates
The bulk feeding in open grasslands and savannas resulted in increase of general herbivore size. For example unugulates (animals with hoovese) continued to grow in size -
Plate tectonics during the Miocene epoch
During this epoch, the plate tectonics were close to what our plates look like present day. The Indian plate was still crashing into the Eurasia plate, so the Himalayas were experiencing constant uplifting. -
Period: to
Miocene Epoch
Miocene Epoch spanned from 5.3 million years ago to 23.03 million years ago. -
Appearance of Kelp forests and grasslands
*20 million years ago
This event, along with the appearance of grasslands is one of the most important events that occured during the Miocene. This event caused new species to appear and evolve.
Kelp forests and grasslands appeared during this Epoch due to a change of cooling climate. These two biomes supported a majority of the life during this time period. -
First Appearance of Grasslands
After mountain ranges appeared in western United States, this changed the climate, causing grasslands to appear. While forest ecosystems decreased, grasslands spread. Fibory, fire-proof grasses grew in grasslands, so many of the animals were grass grazers.There were lots of wildflowers in the grasslands such as thistles, which still exist today. -
Prehistoric Horses Evolved
Due to the increase of grasslands, prehistoric horses evolved to something close to their current form. -
Pliocene Environment
Pliocene environments were generally cooler and drier, as revealed by the remains of plants and trees, but research indicates that around 3–3.5 million years ago may have been a relatively warm period, at least in the North Atlantic. Older groups of animals became extinct throughout the preceding Miocene Epoch. -
Mass Extinction
A mass extinction during the Miocene epoch occurred in the middle of the miocene epoch. Many herbivores and grass grazers became extinct. Scientists believe that global cooling and changes in climate damaged ecosystems, which triggered mass extinction. -
Apes and Hominids Roamed the Earth
Scientists have called the Miocene Epoch the golden age of apes and hominids. During this Epoch, evolving hominids roamed the Earth. The remains of these hominids give us insight and dating to the evolution of humans! -
Rhamphosuchus Roamed the Earth
The Rhamposuchus was traditionally thought of as one of the largest crocodiles that ever roamed the Earth. It lived in the swamps of India during the late Miosene Epoch. Recently after further research, the Rhamposuchus is estimated to be about 8-11 meters in length and 2-3 tons in weight. It was a dangerous predator that had a pointed snout to help catch prey. -
Chimpanzees diverge from hominids
Chimpanzees branched off from hominids 6 million years ago. Chimpanzees are humans' closest relatives, so this event st arted chimps' own path towards evolution of humans. 94% of chimp's DNA matches those of humans. -
The End.
By the time the Miocene epoch was closing, almost all of the modern species of whales were swimmng in the oceans, a large variety of brids roamed the skies of Europe, and the first walruses were living as well. The miocene epoch had modernly developed animals, as well as evolving animals too.
*Planktons and mollusks evolved and diversified during this epoch. -
Period: to
Pliocene Epoch
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Glaciated
Up to 30% of the Earth's surface was glaciated during the Pleistocene. Large portions of Europe, North America including Greenland, South America, all of Antarctica, and small sections of Asia were entirely covered by ice. Because so much water was taken up as ice, global sea level dropped approximately 140 meters. -
Forming of Land Bridge Ables Migration
The creation of a land bridge abled species to migrate between the two continents. This led to a migration of armadillo, ground sloth, opossum, and porcupines from South to North America and an invasion of dogs, cats, bears and horses in the opposite continents. -
Eocene & Ice Caps
This long term cooling, started in the Eocene and continued up to the ice ages of the Pleistocene. During the Pliocene, large polar ice caps started to form and Antarctica became the frozen continent that it is today. -
Reptiles
Alligators and crocodiles died out in Europe as the climate cooled. Venomous snakes continued to increase as more rodents and birds evolved. Rattlesnakes first appeared in the Pliocene. -
Grassland & Savannas
The cooling and drying of the Pliocene formed grasslands and savannas.The Mediterranean Sea dried up completely and remained plains and grasslands for the next several million years. The change in vegetation was a major factor. Long-legged grazers came to live in these areas.
Grazers became larger and developed larger teeth suitable for a diet of grass. Also, longer legs they developed abled them to walk longer distances to new feeding grounds and to detect and escape predators. -
Scorpius-Centaurus OB
In 2002, Narciso Benítez, calculated that roughly 2 million years ago, around the end of the Pliocene epoch, a group of bright O and B stars called the Scorpius-Centaurus OB passed within 130 light-years of Earth and that one or more supernova explosions gave rise to a feature known as the Local Bubble. A close explosion could have damaged the Earth's ozone layer and caused the extinction of some ocean life.
