In Estonia, the fossil of the ancient eye

Scientists say they have discovered in Estonia the fossil of perhaps the oldest eye ever found in a living organism, dating to about 530 million years ago.

The eye, which belonged to a long-extinct marine organism, a species of trilobite (named Schmidtiellus reetae), looks quite like a very early version of the eye that later evolved into some animals such as crabs, bees and dragonflies.

Because the eye is partially damaged, scientists were able to study the internal structure and anatomy of the organ. Among other things, it carries about 100 particles, the tiny photosensitive cells that exist in modern eyes, although in much larger numbers now. On the other hand, the paleo-animal eye does not have a lens.

Researchers from Britain, Germany and Estonia, led by University of Edinburgh professor Juan Clarkson, who published in the journal National Academy of Sciences (PNAS), estimate that the ancient creature had a relatively low relation to today's animals. However, he could see obstacles and potentially dangerous predators in the shallow waters where he lived.

"Our discovery reveals something remarkable: that the structure and function of the eyes have changed little over the last half-billion years," Clarkson said.

The researchers said they found it relatively unlikely to find a relatively intact composite eye older than the one they discovered in the Baltic.