Tertiary Period

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Tertiary Geological Period

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The tertiary period ( also referred to as the Paleogene period and Neogene period) represents the first geological period in the Cenozoic era. The tertiary geological period lasted from approximately 66 million to 2.6 million years ago.  The tertiary geological period began with the death of non-avian dinosaurs (any dinosaurs that are not birds) in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to Quaternary glaciation at the end of the Pliocene Epoch. The dates have been further adjusted as Science advances when new evidence is found. 

Tertiary Time Period

The tertiary time period began about 66 million years ago with a mass extinction that noticed the dinosaur and ended when the ice ages of the Quaternary Period began, about 2.6 million years ago.

Tertiary Period Epochs

Following are the Five Tertiary Period Epochs:

  1. The Paleocene Epoch (first epoch of the tertiary period) lasted from 65 to 55.8 million years ago. This epoch marks the beginning of the Cenozoic era and the tertiary period.

  2. The Eocene Epoch (second epoch of the tertiary period) lasted from about 55.8 to 33.9 million years ago

  3. The. Oligocene Epoch (third epoch of the tertiary period) lasted from about 33.9 to 23 million years ago.

  4. The Miocene Epoch (fourth epoch of the tertiary period) lasted from about 23 to 5.3 million years ago.

  5. The Pliocene Epoch (fifth epoch of the tertiary period) lasted from about 5.3 to 2.6 million years ago.

Tertiary Plants

The tertiary plants closely resemble the plants that we have at present. The warmer climate of the tertiary period, in the beginning, favored dense forests. As the climate cooled, it opened woodland and grassland became abundant. The grasses played an important role during the tertiary period as they supported a large herd of grazing animals. 

Tertiary Period Climate

The tertiary period climate during the beginning was very warm and moist compared to today's climate. Much of the Earth was tropical or subtropical. Plant trees grew as far North as Grasslands. The climate began to cool by the middle of the tertiary i.e. during the Oligocene epoch. The cooling trend of the climate continues and by the Pliocene epoch, ice had begun. 

Tertiary Period Animals 

During the start of the tertiary era, the first large mammals and primitive primates were largely seen. Soon, at the start of the second epoch of the tertiary period i.e. Eocene epoch, the first modern mammals began to appear, and within a short span, most modern mammals were observed. Reptiles during the tertiary era were replaced as the dominant vertebrates by mammals. Fossils reveal that during the early tertiary era, birds, reptiles, fish, and amphibians were also seen. The earliest observed hominid relatives of humans, Proconsul and Australopithecus, also appeared during the Tertiary era. Modern families of flowering plants were also developed whereas marine invertebrates and non-mammal marine vertebrates experienced only moderate evolution.

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Tertiary Period Major Events

In terms of tertiary period major events, the tertiary era covers the major demise of dinosaurs and the beginning of the most recent ice age. At the start of the tertiary period, reptiles were replaced by mammals as dominant vertebrates. Furthermore, all the non-avian dinosaurs also became extinct. Modern types of birds, reptiles, fish, amphibians, were numerous at the beginning of this period, but also continued to appear early on, and also the new age families of flowering plants evolved. At last, but not least the earliest recognizable hominid relatives of humans also appeared. 

With respect to the geology, there was a plethora of tectonic activity that continued from the previous eras, culminating in the division of Gondwana and the clashing of the Indian landmass with Eurasian plates. This caused the formation of the Himalayas, the gradual establishment of the continent of Australia, the separation of South America from West Africa and its connection with North America, and Anatatrica taking its present position below the South pole.  

With respect to the climate, the period was marked by extensive cooling at the beginning of the Paleocene with tropical - to - moderate global temperature and ending before the first massive glaciers at the start of the Quaternary.

 Did You Know?

  • The tertiary period is the period that belongs to the Cenozoic era.

  • The Cenozoic era was further divided into Palaeogene, Neogene, and Quaternary periods. The Palaeogene and Neogene periods are togetherly known as the tertiary period.

  • The Paleogene period is further subdivided into the Oligocene epoch and the second epoch of the tertiary period i.e. Eocene epoch and the Pliocene epoch. Each of these epochs contributed to the life forms, species, and other different factors of the tertiary period.

  • The second epoch of the tertiary period starred 65 million years ago with a span of 17 million years. It was one of the dominant parts of the Paleogene period and contributed immensely in the life of the development of the Paleogene period.

  • The tertiary period includes the present-day configuration of the continents, the cooling of global temperatures, and the rise of mammals as the planet's dominant vertebrates.

  • The tertiary era falls between the Mesozoic and the Quaternary, although no longer recognized as any formal unit by the International Commission on Stratigraphy. 

  • Italian geologist Giovanni Arduino in 1760 introduced the name “ Tertiary’

  • The present Geological time scale uses the terms Paleigen and Neogene rather than the Tertiary. It observed the three periods of geological time including the Quaternary, in the Cenozoic era.

FAQ (Frequently Asked Questions)

1. Which Mammals were Widely Observed during the Tertiary Period?

Ans: The tertiary period is divided into 5 epochs namely palaeocene, Eocene, Oligocene, Miocene, Pliocene. During the tertiary period, mammals diversified rapidly. Some examples were bears, hyenas, insectivores, whales, dolphins, walruses, rabbits, monkeys, apes, lemurs, hippopotamus, hoofed mammals, early mastodons, seals, horses, rhinoceros, rodents, oreodonts, and humans ( Australopithecus).

2. What was The Earth’s Average Temperature at the Time of the Tertiary Period?

Ans: The tertiary period lasted 63 million years. During this period, Earth's average temperature steadily increased from Cretaceous greenhouse temperatures that were between 20 to 26 degrees down to the scary lows of the Pleistocene ice age that was an average of 5 degrees.

3. How did the Tertiary Period End?

Ans: The cooling climate of the tertiary period led to the huge glaciers at the poles. The mountains along with the newly formed Himalayas and alps were also covered with glaciers. The huge amount of water locked up in the sea lowered the level of sea and land bridges that appeared between Asia and North America, Great Britain and Europe, and South Asia and Borneo. This enables the migration of both plants and animals across these land bridges. The tertiary period which had begun hot and humid ended with a cold dry Icy age.