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 lava flows, the hot, dense material that erupts from volcanoes and sometimes reaches high speeds. 200 meters (656 feet) per second. It usually burns any living organisms in its path, but this may change in the marine environment.
“The sea surface over which the ash flowed would have been lethally hot, and would have burned animals at shallow depths,” says the study co-author. Dr. Greg Edgecombe From the Natural History Museum, London, to IFLScience. “The ash likely mixed with seawater during its capture and trapping of trilobites that lived on the sea floor. This mixing in a column of seawater must have cooled the ash sufficiently.”
The ancient wonders, collected in the High Atlas of Morocco, were given the name “Pompeii” trilobites due to their remarkable preservation in ash. They’re incredibly old, but they’re not the oldest trilobites ever found.
It is about 508 million years old, younger than the oldest trilobites, which date back to about 521 million years ago. There is also an even older burrow-shaped trace fossil, called Rusophycus, which is thought to have been the work of trilobites and is over 528 million years old.
However, comparative groupers are still remarkable in terms of the degree of preservation they exhibit.
“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.”
Microscopic reconstruction of the trilobite Gigoutella mauretanica in ventral view.
Image credit: © Arnaud MAZURIER, IC2MP, University. Poitiers
“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’re now seeing trilobites that are closer to life than we’ve ever seen them before, complete with a slit-like mouth and unique vertical feeding appendages. Isn’t that beautiful?
The study was published in the journal Sciences.
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