Origin of Koalas & their Evolution

According to the fossil records, Koalas have been living on earth for about 30 million years (some also quote 25 million years too). Thirty million years ago, Australia was already separated from Gondwana and it had significantly drifted away from it. Therefore; we can also safely assume that koalas have been living on the continent of Australia for 30 million years as well. However; even within these 30 million years different genera of koala had existed and thrived over the years.

Koalas have been living on earth at the Australian continent for almost 30 million years. However; modern koalas only arose 4.5 to 2 million years ago from the Phascolarctos genera.

These genera included Litokoala, Madakoala, Perikoala, Koobor and Phascolarctos. Today’s koalas belong to Phascolarctos genera and is believed to be in its current from the last 4.5 to 2 million years. Therefore; the modern-day koalas in their current form is living on earth from the last 4.5 to 2 million years while the overall koala family species arose some 30 million years ago.

Koalas living on earth for 30 million years
Koalas have been living on earth for almost 25 to 30 million years. Photo courtesy of  

Koalas Living on Earth
More than 30 Million Years Present Day Koalas
Emerged 2 Million Years Ago Recent Ancestors of Koalas
Litokoala, Madakoala, Perikoala, Koobor & Phascolacrctos

Koalas have been living on earth for millions of years.
Koalas have been living on earth for millions of years. Even 30 million years ago, they had their dominant existence on earth. This picture belongs to 

It is also believed that koalas 30 million years ago koalas had a different lifestyle and they used to live in rainforests. They had a diversified diet and were not only relying on the Eucalyptus leaves as part of their diet. However; about 15 million years ago Australia was suffering from the frosty drought which led to the emergence of the drought tolerant plantation such as the Eucalyptus trees. Koalas at that time desperately adapted to the Eucalyptus trees and today’s koala species are the continuity of such koalas.

Today’s Eucalyptus eating koalas are the continuity of the koala group which adopted to the Eucalyptus trees about 15 million years ago.

At the same time some other relatives of koala family demised while the modern day’s Eucalyptus eating koala thrived and increased in numbers. Therefore; the rise of the Eucalyptus plantation during the frosty drought in Australia also led to the rise of the modern-day koalas at the Australian continent.

Eucalyptus eating koalas emerged in Australia some 15 million years ago.
The present day's Eucalyptus eating koalas emerged in Australia about 15 million years ago. Photo courtesy of  

Koalas of 30 Million Years Ago
Lived in Rain Forests Eucalyptus Eating Koalas
Emerged 15 Million Years Ago Other Koalas Became Extinct
Because of Droughts Eucalyptus Eating Koalas
Thrived even with Droughts

Koalas arrived at the continent of Australia about 50 million years ago.
Koalas arrived at the Continent of Australia for about 50 million years ago from the Continent of Antarctica. This Picture belongs to 

But what about the koalas’ presence beyond 30 million years ago? Did they have any relatives at that time? It is speculated that beyond 30 million years ago, koalas only had their ancestors roaming freely at the Australian continent. At that time koalas were literally not koalas but some other animal which had a core preference to feed from grasslands as well as trees. In fact; these ancestors were the ones which separated from the wombat ancestors about 42 million years ago.

Before 30 million years and after 42 million years ago, koalas’ ancestors named as Diprotodonts used to roam across the continent of Australia. They were huge in size and weighed almost two ton.

The koala ancestors which separated from wombats are classified as Diprotodonta. Diprotodonts were huge animals with two big front teeth and they weighed almost two tons. Therefore; in between 30 million years and 42 million years ago, koalas were in fact Diprotodonts with a huge appetite. These arguments indicate that koalas were living 42 million years ago as Diprotodonts.

Koalas' ancestors named as diprotodonts existed 42 to 30 million years ago.
Most recent ancestors of koalas were diprotodonts which existed in between 42 to 30 million years ago. Photo courtesy of  

42 to 30 Million Year Ago
Koalas' Ancestors Used to Exist Koalas' Recent Ancestors were
Diprotodonta or Diprotodonts Diprotodonts were
Huge Animals (Weighing 2 Tons) Diprotodonts Seperated
From Wombat-Koala Common Ancestor

Koalas lived at Anatarctica before Australia about 50 million years ago.
Before coming to Australia, Koalas frequently lived throughout the continent of Antarctica. This picture belongs to 

Today; wombats are the only closest relatives of koalas across the continent of Australia. Both wombats and koalas are thought to be a single animal beyond 42 million years ago from which the koalas’ ancestors and wombats’ ancestors evolved. Furthermore; it was the common ancestor of koalas and wombats which entered the Australian continent about 55 million years ago from the South America.

Beyond 42 million years ago, koala and wombat had a common ancestor. Its size is not known but it is believed that their common ancestor was a burrower living underground with a keen motivation to climb trees for food.

Therefore; this ancestor would have played a fundamental role to derive marsupials at the Australian continent too. The koala and wombat’s common ancestor was believed to be a borrower who used to live underground but also had a motivation to climb trees as well.

Wombats & Koalas had a common ancestor some 42 million years ago.
Wombats & koalas had a common ancestor before 42 million years ago. Photo courtesy of  

Wombats are the
Closet Ancestors of Koalas Alive Today Wombats & Koalas
Seperated 42 Million Yeares Ago Before 42 Million Years Ago
Wombats & Koalas had Common Ancestor Common Ancestor of Wombat & Koala
Entered Australian Content 55 Million Years ago

Koalas have an historical existence at Planet Earth.
Picture of a young Koala Joey at a Zoo in United States. Koalas did have a historical existence throughout the ages at planet earth, that goes beyond 50 million years ago. This picture belongs to 

However; if we track the life of koala’s ancestors beyond the common ancestor of the koala and wombat family, we actually reach the origin of the marsupial mammals. According to paleontologists, both marsupials and placental mammals arise from the Eurasian continent about 125 million years ago. Therefore from 125 million years to 55 million years ago time period, a lot of marsupial mammals evolved from their earliest ancestors and one those ancestors was the common ancestor of koalas and wombats.

Koalas and wombats’ common ancestors are believed to have been emerged from one of the earliest marsupials which arise at the Eurasian continent about 125 million years ago.

This explanation leads us to conclude that koalas only existed in the form of their earliest ancestors from 55 million years and back. Furthermore; their very earliest ancestors were strikingly different than the evolved family of koalas.

Earliest Ancestors of Koalas
Arose 55 to 125 Million years Ago Earliest Ancestors of Koalas
Were Earliest Marsupials Earliest Ancestors of Koalas
Arose alongside Placental Mammals

Koalas earliest ancestors arose 125 million years ago at the Eurasian continent.
The earliest ancestors of koalas emerged at the Eurasian continent (Gondwana) some 125 million years ago. Photo courtesy of 

Regarding answering the question about counting the koalas’ existence on earth, we have multiple scenarios yet specific time periods.

For example, the modern-day koalas have been living on earth about 4.5 to 2 million years ago.
Koalas having adaptation for Eucalyptus have been living on earth from 4 million to 15 million years ago.
Freshly evolved koalas have been living on earth in between 30 to 15 million years ago.
Koalas’ ancestors (Diprotodonts) have been living on earth between 42 to 30 million years ago.
Koalas’ and wombats’ common ancestor had been living on earth in between 42 million years and back while the original ancestors emerged about 125 million years ago from Eurasian continent.

In the final remarks, we can conclude that koalas throughout their lives have gone through an extraordinary journey of evolution that is spanned over millions of years. Furthermore; this extraordinary journey not only involves transformation but also the historical migration of their ancestors as well.

Koalas have 125 million year old history at the planet earth.
Koalas have a rich history of 125 million years in which they had a lot of earliest ancestors, common ancestors and recent ancestors. Photo courtesy of