[Geography Notes] on Miocene Pdf for Exam

In the Neogene Period, Miocene is the first geological period, this extends approximately from 23.03 to 5.333 million years ago. The name ‘Miocene’ was given by Charles Lyell, a Scottish author. This name comes from the Greek word ‘meiōn’ which means ‘less’ and from the word καινός which means ‘new’ this together means ‘less recent’. The Miocene period is preceded by the Oligocene period which is followed by the Pliocene period.

When the earth revolved from the Oligocene period to the Miocene and then into the Pliocene, the climate slowly became cooler and initiated the Ice Ages. If we trace back to the Miocene period, they are not demarcated by boundaries but consist rather of the regionally defined boundaries between the Oligocene which was a warmer age, and the Pliocene Epoch, a cooler age.

Miocene Period

With the commencement of the Miocene period, the earth faced an era of Miocene which had its own distinct changes. The Miocene earth has undergone changes in regard to the types of vegetation, climate, animals, and habitat. In the Miocene Era, specific animals and plants thrived to grow in the land. We will learn about the era, its vegetation, and animal life in detail in our prevailing section.

Miocene Age

Miocene time, which is also known as the Miocene Epoch marks the earliest major worldwide division of the Neogene period which is about 23 to 2.6 million years ago.

Miocene Age is Divided into:

• Early Miocene Epoch which is about 23 to 16 million years ago. 

• Middle Miocene Epoch that is 16 to 11.6 million years ago.

• Late Miocene Epoch that is 11.6 to 5.3 million years ago. 

The Miocene Period is then Divided into Six Stone Ages from the Oldest to the Youngest Stages. They are as follows:

1. The Aquitanian

2. The Burdigalian

3. The Langhian

4. The Serravallian 

5. The Tortonian

6. The Messinian 

The Miocene Age was followed by the Oligocene Epoch which is under Paleogene Period, after which the age was succeeded by Pliocene Epoch.  

We can see the Miocene period closer than other geological periods as their occurrence is recent than other periods. This helps us to interpret and understand the pattern of the events taking place. 

Miocene Animals 

In this section, we will learn about the Miocene Epoch Animals and Miocene Organisms that survived in this period. 

With the advent of diversification in the vegetation, another diversification of the temperate ecosystems consisting of the morphological changes in animals was witnessed. The mammals and birds which are particularly developed from their new forms, which are fast-running herbivores or the large predatory mammals and other birds, which are small quick birds and also the rodents thrived in this diversification. The Miocene Animals are projected below according to their types and diversification, we are putting it in points for a better approach:

1. In this Miocene period, the land-dwelling mammals were very much modern. Many of these animals got extinct by the end of the preceding Oligocene, and half of the mammalian families who are known today are present in the Miocene record. 

2. The Northern Hemisphere faced some interchange of the faunas that occurred between the Old and the New Worlds. This interchange was evident in Eurasia as well. While South America and Australia remained isolated here. 

3. The animal Horse evolved in the Miocene period. This occurred mainly in the Northern part of America.

4. Also, the dogs and bears first appeared at this time. 

5. The emergence of the bear-dog known as Hemicyon happened after few years after the origin of the bears. 

6. Next, from the primitive civets, the first hyenas evolved. 

7. The saber-toothed cats too originated in this time. They are the sub-family of Machairodontinae. 

8. Antelope, Deer, and giraffes also appeared in Eurasia in the Miocene period.

9. While the Ancestors of elephants were limited to Africa. The ancient elephants spread in the Eurasian continent during the Miocene and there they became more diverse in nature.  

10. The Santa Cruz Formation of Middle Miocene time also provides another excellent record of the unusual Miocene fauna of South America.

11. Marsupial Carnivores, aberrant edentates (they are mammals who resemble the anteaters, armadillos, and sloths), here litopterna are also present, they are the hoofed mammals which are quite similar to the horses and camels, these are among the odd groups which are represented here. 

Now, we will display some pictures of these animals from the Miocene Age:

Moropus is an extinct genus of the chalicotheres 

Toxodon – They were the common large-hoofed mammal found in South America. 

This is a picture of Chalicotherium, which is a Miocene mammal. This mammal is from Kazakhstan. Chalicotherium mammal was an “odd-toed” hoofed mammal. Here the perissodactyls and the artiodactyls went through a period of rapid evolution during the Miocene period.

Miocene Plants 

While we study the pattern of the biological change for the Miocene, this informs about the open vegetation systems like the deserts, tundra, and grasslands. Here the closed vegetation types or the forest was not much noticeable. 

When we study the plant in the Miocene age studies, the Miocene is primarily focused on the spores and pollen. Miocene plant studies are represented by the end of the Miocene, in which 95% of modern seed plant families existed, here no such families have gone extinct till the middle of the Miocene. The mid-Miocene warming is here followed by the cooling that is considered here responsible for the fall in the tropical ecosystems, in the expansion of northern coniferous forests, they have increased seasonality.