If we were to turn back the clock, we'll find that the world is an extremely intense environment. Humans have only recently arrived from across the Bering Strait, and what was once the great northlands of the United States, such as the Great Lakes and Mount Rushmore, is almost all covered in ice. Canada is a frozen land, and Mexico is home to an incredibly dry desert. But although this is back long before we humans were officially on top, we're going to take the journey back even further than that.
We are going to go back even further, to a time long before we humans even existed at all. The climate begins to change drastically, going from incredibly cold to incredibly hot and dry, to incredibly rainy and wet. The ocean currents begin to change drastically as the water flow of the planet shifts and churns. The biggest change is on a continental level as the world slowly begins to merge together. South America slowly splits apart from the North American mainland, the mass of Europe begins to tear apart, and Australia and Antarctica move together into a single landmass.
When the world is finally finished, we look upon a completely different North America. This is America in its ancient days, back at least 65 million years ago. This is a very strange world. The planet is almost completely dry due to volcanic temperaments, and most of the mainland is a continuous sea of volcanic rock and debris, with islands of greenery in between. It is a world where no mammals live, and where birds do not rule the sky. It is a world ruled by dinosaurs.
Welcome to the Cretaceous, a period in Earth's geological history filled with perhaps the most famous and complex of all dinosaurs. The megafauna of the planet was in its heyday during this time. Most of the animals here are big, ranging in size from 30-40 feet in length in even the smallest of their kind. Across the American Northwest, dinosaurs like Triceratops, Torosaurus, Anatotitan, and Ankylosaurus share the landscape with one another, while further north their cousins in Canada live in lusher, but still barren wildernesses.
However, life is on its last leg. New mammals have arisen for the first time; mammals that have been competing with the dinosaurs in ways that they could never accomplish; by being small. Eggs have become incredibly vulnerable, and dinosaurs the size of school busses can barely hold these tiny animals at bay. What's worse, however, is that life is dying out at a geological level. Like deadly cankers, volcanoes slowly belch toxic fumes into the air, blanketing the landscape in deadly levels of natural gasses that can kill in an instant. As the world slowly chokes to death, most of the animals here won't be able to survive as their habitat slowly recedes to little short of a worldwide desert
But the true cataclysm occurs not from the world, but in the cosmos, and soon the sky is rained down upon by fire.
Just above the American Southwest, in a region that will become what is now the Gulf of Mexico, a tremendous fireball collides with the planet. An asteroid, at least ten miles long, crashes into the Earth, igniting the atmosphere and sending clouds of dust and ash across the globe. The resulting firestorm and the following age of blackness will kill out over 80% of everything living, resulting in a very different, and very strange, world a world full of opportunity.
This event is known as the KT Event, the infamous and legendary extinction of the dinosaurs. For many years, scientists have debated what truly caused this mass extinction, but, regardless of what caused it, the reality is simple; 65 million years ago, Dinosaurs ruled the Earth. Less than a blink of an eye in the evolutionary timeline, they were suddenly gone; vanished, with nothing but bones to tell their tale.
But our story doesn't begin here. That would be a tale for another time. Instead, we are going to go back even further. At least 150 million years before now, we look upon a world that is full of strange and often exciting forms of life. It is a world far before the time of destruction and doom that wiped out all life on Earth 65 million years ago. Instead it is a world ruled by even greater giants.
Welcome to the Jurassic, a range in time when life was at its peak. The continents have changed again, this time forming into two mega-continents; Gondwana and Laurasia. Here, life has grown on an exponential level, where the planet is a hothouse world, and the absolute biggest of the dinosaurs now rule the land. All across what will be the Dakotas, Colorado, and Utah, the world's largest reptiles make mass migrations from as far north as Canada to as south as Mexico, feeding upon the fresh greens of forests with their long and powerful necks, and in turn being preyed upon by some of the biggest and most powerful predators ever to live.
In the sky, pterosaurs have made their first wing beats, with pterodactyls flying in the sky alongside them. In the ocean, huge beasts larger than military submarines and big enough to make Jaws look like Nemo hunt for fish and other reptiles in the great inland seas. Reptiles rule the Earth, and watching from the sidelines are the ancestors of birds, early rodents, and the insects; all of whom pale in comparison in the diversity of life of this great age.
But though this is the heyday of life, we are going to go back even further than that. Going backwards in time, we look upon a world where life, surprisingly, is not at all quite as diverse. In fact, life is just recovering from perhaps the greatest disaster it has ever witnessed.
This is the Triassic. The world is much, much different than ever before. All of Earth's continents are merged into a vast super-continent, with a tremendous canyon spanning the center surrounded by a huge, global desert. On all sides lies a series of mountain ranges, perennial forests, and massive coastal territory. What little life exists lives in these regions, where rainfall occurs every year to ensure that life will continue to survive. It is here, in this bleak and desolate planet, where our story begins.
Welcome to North America otherwise known as Northwestern Pangaea