Connect with us

Hi, what are you looking for?

News

This 390-Million-Year-Old Trilobite Fossil Had a Bunch of Tiny Eyes Inside Its Eyes

A fossilized trilobite first studied by an amateur paleontologist half a century ago has provided researchers with a whole new way of seeing the world, in a very literal sense.

 

X-rays taken of the ancient arthropod back in the early 1970s have been given a second look, revealing a structure of an eye that is unlike any seen on any animal before or since.

As head of Siemens radiology department, Wilhelm Stürmer knew a thing or two about using X-rays to reveal hidden secrets. This was especially true when it came to studying fossils, a passion he fueled by fitting out a minibus with X-ray equipment to take out to paleontology sites.

Advertisement. Scroll to continue reading.

In spite of his expertise in radiology, Stürmer wasn’t a paleontologist, so few took his claim of discovering optic nerves inside a 390-million-year-old Phacops geesops fossil seriously.

“At that time, the consensus was that only bones and teeth, the hard parts of living things, could be seen in the fossils, but not the soft parts, such as intestines or nerves,” says University of Cologne paleontologist Brigitte Schoenemann.

In addition to the nerves was an arrangement of ‘fibers’ that looked uncannily like photoreceptor cells called ommatidia. Only in this case, they were strangely elongated, roughly 25 times their own diameter; far too long to seem plausible as a light-gathering structure.

 

Advertisement. Scroll to continue reading.

A lot has changed since then. Today, paleontologists are comfortable with the idea that soft tissue structures can leave a clear signature in fossilized material. And super-long ommatidia have since been uncovered in the compound eyes of aquatic arthropods.

With that in mind, Schoenemann and her colleagues went back to Stürmer’s original images for a closer look. After double-checking the fossil with modern CT technology, they determined the filaments he spotted were almost certainly optic nerve fibers after all.

But it was what the foam-like nest of fibers was connected to that really grabbed the researchers’ attention: What seemed like two compound eyes were actually hundreds, split across left and right clusters.

“Each of these eyes consisted of about 200 lenses up to one millimeter in size,” says Schoenemann.

Advertisement. Scroll to continue reading.

“Under each of these lenses, in turn, at least six facets are set up, each of which together again makes up a small compound eye. So we have about 200 compound eyes (one under each lens) in one eye.”

Trilobites more or less dominated the oceans for hundreds of millions of years, adapting to fill a broad range of aquatic niches with a variety of weird and wonderful body plans.

 

One of their most clever inventions was a visual system of unprecedented complexity. While comparably simple in modern terms, their version of eyes gave them the edge in hunting or hiding and in detecting the subtlest of changes in brightness and movement.

Advertisement. Scroll to continue reading.

Though their eye anatomy came in many forms, the most common structures would be easily recognizable to most zoologists today, consisting of a neatly arranged pattern of lenses working together to turn diffuse light into a heavily pixelated map of their surroundings.

Modern insects and other arthropods continue to rely on compound eyes like these to great effect. What this pixelated view lacks in resolution is easily made up for in simplicity and adaptability, evolving to overcome limitations with a few tweaks of anatomy.

Yet for the incredible diversity of trilobite eyes, those on certain members of the suborder Phacopina have had paleontologists stumped.

In what’s known as a schizochroal eye, each lens sits a short distance away from its neighbor, leaving a lot of empty space that could be put to use catching more light.

Advertisement. Scroll to continue reading.

 

We now know what appears to be a single lens is, in fact, a single compound eye within two ‘hyper-eyes’.

While it doesn’t tell us why these eyes evolved, it does change what questions we need to ask about this unusual arthropod.

Rather than pondering the waste of space between each lens, biologists can now speculate over the benefits hundreds of tiny eyes have in adjusting to low light, or responding to rapid changes in light conditions over a wider area.

Advertisement. Scroll to continue reading.

“It is also possible that the individual components of the eye performed different functions, enabling, for example, contrast enhancement or the perception of different colors,” says Schoenemann.

Stürmer must have suspected there was something worth looking at in the eyes, having drawn an arrow in red pen pointing right at the half-dozen facets beneath one of the lenses.

Sadly, the radiologist passed away in the 1980s, long before his discovery was given the validation it deserved.

Like the trilobite, Stürmer was clearly a visionary before his time.

Advertisement. Scroll to continue reading.

This research was published in Scientific Reports.

 

Advertisement. Scroll to continue reading.
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Technology

Developed by Leonardo da Vinci, one of the most amazing engineers ever born, it is an example of a bridge that you can build...

News

Now, possibly more than ever before, engineers and scientists happen to be taking inspiration from nature when developing technology. This is especially true for...

News

Playing through the greenery and litter of a mini forest’s undergrowth for just one month may be enough to change a child’s immune system,...

News

It had been only designed to fly five occasions. But NASA’s helicopter on Mars, Resourcefulness, has completed 12 flights also it is not prepared...

News

The Sun’s Rays is definitely showering Earth with a mist of magnetized particles referred to as solar wind. Typically, our planet’s magnetic shield blocks this electric wind from...

News

A police raid in South america has saved our scientific understanding of the incredibly well-preserved flying lizard that sported an unbelievably large mind crest....

News

Now, perhaps more than ever, engineers and scientists have been taking inspiration from nature when developing new technologies. This is also true for the...

News

Climatic change has already been affecting people’s health a lot that emergency action on global warming can’t be placed on hold as the world...

News

Elite athletes – like Jakob Ingebrigtsen, who won gold for that men’s 1,500 meter race in the Tokyo, japan 2020 Olympic games – train...

Advertisement