Trilobites Turned Out To Have Eyes Inside Their Eyes

A fossilized specimen first studied by an amateur paleontologist half a century ago. trilobitehas literally opened up a whole new way for researchers to see the world.

X-rays of this ancient arthropod in the early 1970s reviewer Researchers have uncovered an eye structure not seen in any animal before or since.

Samples taken in the 1970s were reexamined

Siemens as head of the radiology department Wilhelm StürmerHe had a wealth of knowledge in using X-rays to unearth hidden secrets. This was especially true when it came to examining fossils, a passion he fueled by packing a van with X-ray equipment to go to paleontology sites.

Despite his expertise in radiology, Stürmer was not a paleontologist. 390 million years a phacops geesops His claim that he discovered optic nerves inside his fossil was not taken seriously by many. on the subject University of Cologne paleontologist Brigitte Schoenemann, “At that time, there was consensus that only bones and teeth, that is, the hard parts of living things, could be seen in fossils, but not soft parts such as intestines or nerves.” he said.

In addition to nerves ommatidia resembling photoreceptor cells called “fiber” there was order; but in this case, oddly enough, they were elongated to roughly 25 times their own diameter, far longer than would be reasonable for a light-gathering structure. Of course, a lot has changed since then. Today, paleontologists are aware that soft tissue structures can leave traces in fossils, and in addition, super-long ommatidia have been discovered in the compound eyes of aquatic arthropods.

Each eye consists of about 200 lenses

In light of this information, Schoenemann and his colleagues used Stürmer’s original images for further investigation. again took it. Researchers; modern over fossil CT technologyAfter going through twice, the detected filaments are almost certainly optic nerve fibers determined that.

But what caught the researchers’ attention was what the foam-like loofah was connected to: What appeared to be two joined eyes actually it was hundreds and was divided into left and right clusters. Schoenemann, “Under each of these lenses, in turn, there are at least six facets, each of which again forms a small compound eye. So there are about 200 compound eyes (one under each lens) in an eye.” saying that each of these eyes is approximately one millimeter in size. from 200 lenses reported that it was formed.

trilobitesMore or less dominated the oceans for hundreds of millions of years, adapting to fill a wide range of water niches with their various strange and wonderful bodies. One of the most wonderful inventions of the trilobites is; It was a visual system of unprecedented complexity. This system gave them an advantage when hunting or hiding, detecting the subtlest changes in brightness and movement.

Discovery; brought new questions

What now seems like a single lens is actually two ‘hyper eyes’ We know that there is only one compound eye inside. Although it tells us that these eyes why it evolved While it doesn’t give a clue about what’s going on, it does change the questions we should be asking about this unusual arthropod.

Biologists no longer think about wasting space between each lens; they can speculate on the benefits of hundreds of tiny eyes adapting to low light or responding to rapid changes in light conditions over a larger area. Schoenemann on this “It’s also possible that individual components of the eye perform different functions, for example, enhancing contrast or detecting different colors.” he said.