Pompeii trilobite fossils dating back 508 million years show features never seen before

Trilobites dating back 508 million years have been found preserved in volcanic material, revealing never-before-seen detail in 3D form. Their fossilization was so rapid that small shells were preserved in place, and soft tissues including mouth parts and internal organs can still be seen.

The trilobites were buried in pyroclastic flow, the hot, dense material that erupts from volcanoes and sometimes reaches speeds of up to 200 meters (656 feet) per second. Normally, it incinerates any life in its path, but this can change in a marine environment.

“The sea surface onto which the ash flowed would have been deadly hot, and would have burned animals at shallow depths,” says the study co-author. Dr. Greg Edgecombe From the Natural History Museum in London, to IFLScience. “The ash likely mixed with seawater as it captured and trapped trilobites that lived on the sea floor. This mixing in a column of seawater would have cooled the ash sufficiently.

The ancient wonders, collected in the High Atlas of Morocco, have been dubbed the “Pompeii” trilobites because of their remarkable preservation in the ash. They are incredibly old, but they are not the oldest trilobites ever found.

They are about 508 million years old, younger than the oldest trilobites, which date back to about 521 million years ago. There are also older burrow-shaped trace fossils, called Rusophycus, which are believed to be the work of trilobites and are over 528 million years old.

However, the grouper fish is still remarkable in the degree of preservation it shows.

“What makes our specimens unique, especially pristine, is the preservation of their appendages in 3D,” Edgecombe continued. “The appendages are not flattened, reoriented or broken. They are preserved in their proximal life orientations. Because they are preserved as empty space in the stony matrix, we can image them cross-sectionally to see them in 3D.”

“Appendages preserved in shale can preserve their bristles beautifully, but the fossils are so compressed that they are almost two-dimensional, and we have to use destructive sampling to mechanically drill out the upper parts of the appendages in order to see the lower parts. Our specimens are as perfect after study as they were.” before.”

These never-before-seen details mean we now see trilobites closer to real life than we’ve ever seen them before, complete with a slit-like mouth and unique vertical feeding appendages. Is not she beautiful?

The study was published in the journal Sciences.