“Hearst Magazines and Yahoo may earn commissions or revenue from some articles through these links.”

• Scientists have discovered a remarkable fossilized larva with its brain and intestines still intact.

• The fossilized animal is one of the earliest ancestors of a group called arthropods, which includes insects, crabs and lobsters.

• This ancient animal offers experts a unique window into the past, allowing them to better understand the evolutionary connections between the arthropods of Pasta and those of today.

We know what fossils look like. Typical dinosaur fossils, for example, are bones that have turned to stone and have been preserved over time. If we’re lucky, they’re in large collections that can be reassembled to fully represent the animal they once supported.

Now, not all fossils are like this. Some are just impressions of small creatures or animals left in rocks, but most have one thing in common – it’s just the hard material that’s left behind. Except for fossils found in particularly well-preserved environments, the soft tissue decomposes over time and all that’s left is stony bone.

But not always. Sometimes we are lucky – like a team of researchers who recently found the fossil of a 520 million year old worm larva that still had a brain and intestines. intact.

“It’s always interesting to use 3D images to see what’s inside a specimen,” Katherine Dobson, co-author of a new study focusing on this remarkable find, said in a press release, “but in this incredibly small larva, natural fossilization has achieved near-perfect preservation.”

This “near-perfect preservation” made the specimen a goldmine for evolutionary biologists. According to the press release, the structures observed inside the creature — which were examined using 3D images created from scans using a technique known as synchrotron X-ray tomography — include a brain, “digestive glands, a primitive circulatory system, and even traces of the nerves that supplied the larva’s simple legs and eyes.” The incredible amount of detail preserved in this ancient fossil showed scientists that we had previously dramatically underestimated the complexity of early arthropods — a group that arose during the Cambrian explosion and includes creatures such as crabs, lobsters, insects, and millipedes.

This detail also allowed scientists to make evolutionary connections between the ancient creatures and those scurrying around today. For example, a brain area known as the protocerebrum was preserved in the larva. Now that scientists have studied it, they can see that it evolved into the “knot” of arthropod heads that allowed them to survive in so many different environments—from the depths of the ocean to every single continent on Earth (yes, including Antarctica).

“When I used to dream about the one fossil I’d most like to discover,” Martin Smith, the study’s lead researcher, said in a press release, “I always thought of an arthropod larva because developmental data is so important for understanding their evolution. But larvae are so tiny and fragile that the chances of finding a fossilized larva are virtually zero – or so I thought! I already knew this simple worm-like fossil was special, but when I saw the amazing structures preserved beneath its skin, my jaw dropped – how could these intricate features escape decay and still be visible half a billion years later?”

Currently, scientists are happy that the creature has been preserved at all, giving us a unique insight into life in our distant past.

You might also like