As a species jellies have been around for a very long time. They appeared in the oceans about 650 million years ago, before the dinosaurs. They still populate our oceans today in a profusion of sizes and shapes.
Jellyfish are incredible creatures - it's amazing that they are living things.
They are one of earth's simpler and more primitive life forms. The picture you see at left is a much smaller specimen of a lion's mane jelly. The world-record holder was found dead, washed up on a beach. Scientists have determined that some jellies have eyes that can detect light from dark and even some movement of objects in their field of vision. The brain is where the processing of visual stimuli happens in most higher-order species.