390 million year old trilobite fossil with a pair of tiny eyes in its eyes

The fossilized trilobites, which were first examined by an amateur paleontologist half a century ago, gave researchers a whole new way of looking at the world in the truest sense of the word.

A second examination of x-rays taken of ancient arthropods in the early 1970s revealed an eye structure that is different from that of any other animal before or after.

As head of radiology at Siemens, Wilhelm Stürmer knew how to use X-rays to reveal hidden secrets. It was especially true When it came to researching fossils, his passion was equipping a minibus with X-ray machines to take it to paleontological sites.

Despite his expertise in radiology, Stormer was not a paleontologist, so few have claimed to have discovered the optic nerves in a 390 million year old person. Vacobs Jessups Fossil seriously.

“At that time it was agreed that only bones and teeth, the hard parts of living beings, could be seen in fossils, but not the soft parts such as the intestines or nerves. He says The palaeontologist of the University of Cologne Brigitte Schönemann.

Next to the nerves there was an arrangement of “fibers” that looked suspiciously like the so-called photoreceptor cells. Umatidy. Only in this case were they strangely elongated, about 25 times their diameter; So big that it makes sense as a light collection structure.

A lot has changed since then. Today paleontologists are content with the idea that soft tissue structures in fossil materials can leave a visible imprint. Ultra-long ommatidia It has since been revealed In eyes composed of water arthropods.

Against this background, Schönemann and his colleagues took a closer look at the original photos of Stürmer. After re-examining the fossil using modern CT technology, they determined that the leads it discovered were almost certainly nerve optic fibers.

But what connected the moss fiber nest was what really caught the researchers’ attention: What looked like two compound eyes were actually hundreds, divided into groups on the right and left.

“Each of these eyes consists of around 200 lenses up to one millimeter in size”, He says Barn man.

“At least six sides are prepared under each of these lenses, each of which in turn forms a small compound eye. So we have about 200 compound eyes (one under each lens) in one eye.

Trilobites in one form or another have dominated the oceans for hundreds of millions of years, adapting to fill a myriad of water holes with a myriad of weird and wonderful body planes.

One of their smartest inventions was a visual system of unprecedented complexity. Although relatively simple in modern terms, their version of the eyes gave them an advantage in hunting or hiding and in spotting the slightest changes in light and movement.

Despite the anatomy of her eyes It came in many forms, the structures most familiar to most zoologists today are easy to spot, consisting of a pattern of finely arranged lenses that work together to convert stray light into a highly pixelated map of their surroundings.

Modern insects and other arthropods continue to rely on compound eyes like these with good success. What is this fraction offer? Lack of precision Easy compensated In simplicity and adaptability, it evolves to overcome limitations with some modifications to the anatomy.

As for the astonishing variety of eyes of the trilobites, however, those of some members of the suborder vaccine Paleontologists were confused.

in what one a. is called schizophrenic eyeEach lens is a short distance from its neighbor, which leaves a large empty space that can be tapped to capture more light.

We now know that what looks like a single lens is actually a single eye made up of two “very attentive eyes”.

While that doesn’t tell us why these eyes developed, it does change the questions we need to ask ourselves about this unusual arthropod.

Instead of thinking about wasting space between each lens, biologists can now speculate on the benefits of having hundreds of tiny eyes to adapt to dim light or to respond to rapid changes in lighting conditions over a larger area. .

“It is also possible that the individual components of the eye fulfill different functions, for example being able to improve the contrast or the perception of different colors”, He says Barn man.

Stormer must have known there was something worth looking in the eye after drawing an arrow with a red pen that pointed directly to the half-dozen dials under one of the lenses.

Unfortunately, the radiologist died in the 1980s long before his discovery received the confirmation it deserved.

Like the trilobites, Stormer was clearly a visionary ahead of his time.

This study was published in Scientific reports.