For most of Earth’s history, the continents were a lifeless stage. Wind sculpted bare rock. Rivers cut through stone. The waves broke against empty shores. Life flourished in the oceans, but the land above the tide line was a silent world — sunlit, storm-battered, and sterile.
> Then, around 420 million years ago, the silence began to change.
In the Silurian Period, the first true green arrived on land. Not forests, not fields, not anything we would recognize as a landscape — but something far more fragile and revolutionary: tiny upright plants, only a few centimeters tall, pushing their way into a harsh new realm. They were pioneers with no leaves, no flowers, no seeds. Some looked like green matchsticks. Some branched into simple forks. They grew low and sparse along river margins and damp coastal flats, where the water lingered and the rock had begun to crumble into the first thin soils - wikipedia 
These early land plants, often represented by fossils like Cooksonia, carried a crucial invention inside their stems: vascular tissue. It was a living plumbing system — a way to lift water upward and hold the body upright. With it, plants could do something algae could not. They could stand, reach into the air, and begin to claim the continent.
The world they entered was not welcoming. Ultraviolet light was stronger than today. The ground offered little nutrition. Dryness was a constant threat. Yet the reward was immense: sunlight without competition, space without predators, and carbon dioxide in abundance. In those damp corners of the planet, the first green line held.
> And then it began to spread.
As these plants lived and died, they left behind organic matter. They trapped dust. They steadied sediment with primitive roots or root-like structures. Over time, their bodies helped transform raw mineral ground into soil. In doing so, they changed the chemistry of the Earth itself: drawing carbon from the air, influencing weathering, and helping oxygen rise in the atmosphere. The planet was being re-tuned, very slowly, by a new kind of life that worked on geological time.
> The first green land did not look like paradise. It looked like a beginning.
If you stood there — on a Silurian riverbank — you would not see a world transformed. You would see a thin, tentative fringe of life hugging the water’s edge. But in that narrow green margin lay the future: forests, insects, amphibians, reptiles, mammals, and eventually the creatures who would name this moment and marvel at it.
> The land was no longer only rock. It had learned its first living color.
# See - Life on Land and the First Land Animals