500 million years ago, Earth was a dramatically different planet. The continents were arranged in a single supercontinent called Gondwana, and the climate was much warmer and wetter than today. The oceans were teeming with life, including giant trilobites, nautiloids, and early fish. The land was mostly barren, with only a few primitive plants and animals. Over time, the continents began to break apart and drift toward their current positions, and the climate began to cool. This period of change marked the transition from the Proterozoic to the Phanerozoic Eon, and set the stage for the evolution of complex life on Earth.
