Sharks Predate Trees by Millions of Years

Long before the first forests stretched across the continents, our planet's oceans were already home to the ancestors of modern sharks. The earliest, whisper-thin evidence we have of sharks are fossilized scales dating back 450 million years to the Late Ordovician Period. During this time, Earth was a very different world, with most life thriving in warm, shallow seas and the continents configured into a giant landmass called Gondwana. These ancient swimmers existed in an ocean filled with trilobites and other marine life, long before the first vertebrates would venture onto land.

It wasn't until the Devonian Period, roughly 100 million years later, that the first true trees began to take root on barren ground. Early plants had started to colonize land, but they were small and low to the ground. The evolution of tree-like plants, such as *Wattieza* and *Archaeopteris*, was a revolutionary step. These early forests, which reproduced with spores instead of seeds, fundamentally changed the planet. Their growth pulled massive amounts of carbon dioxide from the atmosphere, creating more oxygen and paving the way for larger terrestrial animals to evolve. Sharks, meanwhile, continued to cruise the oceans, surviving multiple mass extinctions and diversifying into the successful predators we know today.