Around 350 million years ago, giants lived on Earth, such as the enormous dragonfly Meganeura monyi. This so-called “griffinfly” was the largest flying insect ever to exist, with a wingspan of over 70 cm—about the size of a crow. Imagine one of these flying toward you!

During this period, you might also have encountered the massive land scorpion Pulmonoscorpius. At 70 cm in length, it was nearly as large as a house cat. Another remarkable creature was Arthropleura, a giant millipede that could grow up to 2 meters long (see Figure 1). It was the largest land-dwelling arthropod ever to exist.

The largest arthropods, however, lived in water, like the gigantic Jaekelopterus (see Figure 2). These sea scorpions could reach an astonishing length of up to 2.5 meters.

During the Carboniferous period, the Earth was almost entirely covered by forests and swamps. This created a much higher oxygen level than today, which is thought to have allowed insects to grow to such monstrous sizes. Compare today’s insects with their prehistoric relatives!

In the late Devonian period, one of our earliest ancestors evolved. Tiktaalik was a fish that could crawl out of the water using its strong fins as primitive legs. This marked the beginning of vertebrate life on land.

An interesting fact is that certain bacteria and fungi that break down plants did not yet exist at that time. As a result, dead plants accumulated over millions of years, forming thick layers that eventually turned into coal. Without coal and other fossil fuels, the world as we know it would likely look very different today.