Sharks Are Older Than Trees

Long before the first forests blanketed the continents, Earth's oceans were already home to a formidable predator. The ancestors of modern sharks began navigating these waters around 450 million years ago, during the Ordovician Period. These were not the great whites of today, but a diverse group of cartilaginous fish that established a blueprint for survival. Their evolutionary design has proven so successful that they have weathered at least four of the planet's five major mass extinction events, continuing their reign in the seas while countless other species, including the dinosaurs (Review), vanished.

It wasn't until a full 100 million years later, during the Devonian Period, that the first true trees began to take root on land. Pioneering species like Archaeopteris started to form the world's first forests, a revolutionary event for the planet. These new, towering plants fundamentally altered the global climate by absorbing vast amounts of carbon dioxide and releasing oxygen, creating the air we breathe today. They also created complex terrestrial habitats, paving the way for the evolution of land-dwelling animals that would follow. So, while trees were transforming the land, sharks were already ancient veterans of the deep.