A wall of water appears on the horizon rushing across the parched earth.

You're standing on a ledge above the flash flood.

The result of the first significant rainfall this arid landscape has seen all season.

And this flood is especially tragic because caught in the swift-moving muddy current are animals

who had just moments earlier gathered at a small pond to take advantage of the rare drinking water.

They're slender creatures measuring up to three meters long with powerful hind legs.

You recognize them as celophysis, one of the most well-known early dinosaurs.

And these little meat eaters are being swept away by the hundreds.

Their presence means that you are in the late Triassic, around 208 million years ago,

and you found yourself in the middle of an event unfolding in what's now New Mexico.

Just north of the equator on the supercontinent of Pangae, it's a place that has become increasingly

unpredictable. The dry seasons have become drier, and the monsoons that punctuate them are more extreme.

Scrambling to higher ground, you survey the landscape beyond the flood, an area that during

wetter times is rich with fields of seed ferns and forests of conifers in the hills above.

But now, it's a bit of a wasteland. As you walk along, you notice that the air around you is

warm and humid. In the distance, you see something darting across the landscape, being chased

by a celophysus that managed to find itself safely above the flood.

Its prey is a long-tailed early crocodile relative called Hespirosuchus, which runs swiftly by,

balancing on its impressively long hind legs.

The animals at this time look, well, weird to you.

They are somewhat familiar but also different, as if you've landed

on another planet, and things here are about to get interesting. Far to the southeast, heat has

...