A study of 500 metre-deep core samples from sediments along New Jersey's coastline by a team of scientists led by Professor Kenneth Miller suggest sea levels rose and fell frequently by tens of metres soon after the reign of the great dinosaurs had ended. Such fluctuations were only possible if the Earth was not free of ice at this time.

The team made this interesting discovery after studying the type of sediment, the fossils it contained, and changes in the amount of isotopes in different elements within different layers of the sediment core. (1)

 
World temperatures rose by up to 20&#degC over a 20,000 year period around 55 million years ago. There is every indication extra volcanic activity and mountain-building was occuring at this time.

Over the next 5 million years, flowering plants diversified in numbers, allowing a greater number of insects to thrive and an extra source of food for the evolving mammals.

 
According to Dr Jerry Dickens, a scientist and lecturer in biochemistry in the School of Earth Sciences at James Cook University in Townsville, some methane trapped inside cages of frozen water known as methane hydrate ice under high pressure and low temperature underneath 500 to 3,000 metres of ocean along continental slopes suddenly melted and released three or four major and a series of smaller methane emissions into the atmosphere around 55 million years ago.

Because methane is a more effective heat trap than carbon dioxide (at least 20 times more potent), world temperatures rose by at least 10 degrees celsius and so did the sea levels.

 
With far fewer predators of the dinosaur kind roaming around nearly 64.5 million years ago, certain mammals became more curious and adventurous by leaving their burrows, trees, or other hiding places on a more regular basis to search for food. (2)

As these mammals adapted to the open environment, their bodies were able to evolve physically bigger over time. However, brain capacity would probably not have increased significantly until memory, visualisation and communication were understood by certain mammals as important to coping with an increasingly more competitive and changing environment, especially as food supplies dwindled over time and other mammals began competing for their share of the food and other resources.

One of the mammals that evolved a slightly larger brain were apparently tree dwellers living in the tropical jungles around the equatorial regions of the planet. The oldest known primate is a small animal called Purgatorius: it appeared around 65 million years ago eating insects and climbing around in the trees searching for food, and it had excellent eyesight, strong grasping hands and a relatively large brain size.

 
The great mountain range known as the Himalayas is born from the collision of India with the Asian continent.

Antarctica separated from the Australian mainland and moves southward, resulting in the Australian continental shelf suddenly dropping away and forming a massive 5 kilometre deep canyon wall. By 25 to 30 million years ago, Tasmania and South America separated from Antarctica.

Icesheets begin to appear on Antarctica, causing sea levels to fall. Tasmania appears part of the Australian mainland.

 
A type of shrub to have considerable widespread affect on a large number of people from 2,700 B.C. to the present day would originate at this time in a mountainous region of Kazakstan. Out of the thousands of chemicals many plants can stumble upon during their own evolution, one specific plant discovered an effective chemical defense mechanism for protecting the leaves from being eaten by animals (it tastes pretty bad) and to survive longer than most other plants by being extremely resistant to the effects of ultraviolet light. The chemical is known as Tetra-hydro-cannabinol (or THC). We would know the plant today as Cannabis.

In times of great physical pain, people would learn the medicinal secrets of the plant due to the presence of another chemical component known as Cannabidiol (CBD) which provides strong anti-inflammatory and, oddly enough, anti-psychosis relief (should it be needed). But because life is hard and highly stressful, some other people have learned about the THC component of the plant for relaxing the mind and developing a high euphoric feeling.

However, due to the risk of developing the psychosis effects of schizophrenia (because the frontal cortex has stopped functioning over a long period of time) by the long-term use of THC in the cannabis material for a small number of people, and to a greater extent a loss of short-term memory among the young people thereby reducing the chances of these people being productive in society (and hence become an economic burden), it is illegal for people to grow and use the plant.

 
The end of the Eocene Epoch saw the birth of extensive mountain-building in the Andes in South America, the Himalayas in central Asia, and the Rockies in North America. Australia also had its fair share of mountain-building with the appearance of a few volcanoes along Australia's eastern coast.

In Europe, a few volcanoes and numerous hot springs appeared in a region we would call Germany. Some lakes were known to have released poisonous volcanic gases. If the gases exceeded a certan quantity, it can kill the animals. Much of the European continent is heavily forested to support the many unusual mammals of both the herbivore and carnivore types of this time.

As for the wildlife in Australia, they were mainly concentrated in and around the inland sea and numerous freshwater lakes in the central part of the continent. Furthermore, the animals were relatively large and unusual compared to what we now have in Australia today. It is these unusual animals that would form the basis of many great ancient stories for the Australian aborigines.

It is believed by scientists that birds were the dominant creature on land during this period of Earth's history. This is a world where birds would eat animals the size of large tree primates.

In the water, dangerous mammalian predators were plentiful including the ancestors of the whales which existed in both lakes and oceans.