At the end of the 17th Century, a fossil collector named Edward Lhwyd found something in southwest Wales unlike anything he’d ever seen before.

He described it as ‘the  skeleton of some flat fish’ and reported it to the Royal Society, along with a drawing, as the first fossil of its kind to be documented by Western scientists. But this strange fossil wasn’t a fish at all.

It was a trilobite. These animals were some of the most successful creatures to ever live, and studying them has helped scientists to understand more about  ancient biology, evolution, and our planet’s geological past. And Edward Lhwyd may have been the first Royal Society member to spot them, but people all over the world have been fascinated by these fossils for centuries.

In fact, there’s evidence that  we’ve been collecting trilobites for thousands of years. [intro music] Trilobites are an extinct  group of marine arthropods, most closely related to  modern-day horseshoe crabs. The fossils are named for the three lobes going across their bodies, and their shield-like shells are also separated into three parts top to bottom: a head, thorax, and pygidium - which is just a fancy name for the butt. They first appeared on Earth  around 520 million years ago during the Cambrian explosion, and quickly became so successful that the Cambrian period became known as the ‘Age of Trilobites’.

Trilobites thrived in the oceans for some 270 million years, before being wiped out along  with 90% of all life on Earth during the end-Permian extinction. There were more than 20,000 species of them, so they clearly got the whole “go  forth and multiply” thing down. They mostly stuck to the shallow ocean floor, grazing on what they could find and occasionally burrowing through soft sediments, although some could even  swim through the open water.

And some of them decided to add a little flair to their simple three-lobed bodies, from multi-faceted eyes on columns and stalks, to weird spines and headdresses  thought to be used for defense. Some even had a giant ball on their heads that looks like a little clown nose, which might be the cutest thing I’ve ever seen. There’s a lot to like about these guys!

And it’s not just researchers  who care about trilobites. A ll over the world, people have been fascinated by them for centuries. Like, I’m talking pre-agriculture.

At the end of the 19th century, archaeologists discovered a limestone cave in France, filled with artifacts like bone tools and spears, all dating to about 15,000 years ago. Among the debris, they also found something much older - the remains of a 400 million year old trilobite. Now, finding trilobites among limestone isn’t usually that surprising, but this discovery was  remarkable for several reasons.

For starters, there are no trilobites known  from the rocks of that area. So this specimen must have come from somewhere else, meaning that whoever carried it all that way really valued it. While it could have come from elsewhere in France, at least one paleontologist thinks it came from modern-day Czechia, 850 kilometers away.

The other really fascinating  thing about this fossil is that it’s really worn down, and it has two holes drilled into it, indicating that it was handled often and possibly worn as jewelry. What these stone age people  thought the trilobite was, or what it meant to them,  we’ll probably never know. However, French cave dwellers weren’t the only ones to have gathered up trilobite  fossils over the years.

Some of the most beloved trilobites around only reached icon status thanks to the Industrial Revolution. See, when English engineers figured out how to make basically everything easier with steam power, they needed coal, and a lot of it. So they started digging.

In particular, there was  plenty of coal in the area around a town in England called Dudley. They also had plenty of other resources, like iron ore, limestone, and fireclay, which meant that there was  a lot of digging going on. And alongside their ores and coal, miners found a ton of trilobite fossils, mostly of the species Calymene blumenbachii.

The workers called these fossils Dudley locusts, or Dudley bugs. Many of them were the classic  shield-like trilobite shape, but some showed the animal adorably rolled up like a pillbug. And studying the Dudley bug helped scientists figure out that trilobites were in fact arthropods just like pillbugs, albeit very distantly related.

In fact, Calymene was so abundant and so important in the early history of trilobite  science, that for a while, all trilobites were referred to as Dudley fossils. But there are plenty of trilobite-fans on the other side of the Atlantic, too. The indigenous Ute people have been living in the Great  Basin area of North America since around 1000 CE.

And they have historically collected and worn trilobites, in particular a species called Elrathia kingii. This is the most common trilobite  fossil in North America, in part because of where they chose to call home back in the day. Elrathia lived during the middle Cambrian around 500 million years ago, and compared to most other trilobites, this species preferred life on the edge.

They lived at the borderline between anoxic and dysoxic waters. In other words, right at the spot where the oxygen was lowest. Not many animals would have been able to handle such low oxygen, so Elrathia would have had the seafloor pretty much to themselves.

In fact, scientists think that these trilobites may have been the very first animals adapted to survive in such low-oxygen environments. And these environments also just happen to be the best places to be if you want to become a fossil. For a start, there are no other animals around to chow down on the dead bodies, and fewer decomposers to break them down, too.

Plus, the water is fairly calm and still, so their bodies won’t get smashed up by the waves. Finally, there’s always fine sediment raining down from above, making a perfect muddy tomb. Eventually that mud turns into fine-grained shale capable of preserving the finest details of a trilobite exoskeleton.

So Elrathia fossils are super common in the Cambrian rocks of North America, which is why the Ute people of the Great Basin have been able to collect them for centuries. They called them ‘lizard’s feet’ and ‘water bugs’, suggesting they did know the fossils were related to living things. And these fossils were thought to have medicinal properties, too.

Trilobite pendants were  thought to offer protection against everything from sickness to sore throats and even diphtheria. So people around the world have appreciated these fossils long before we even knew what they were. And there are plenty of fossil collectors today who still treasure them.

Speaking of collectors, we have something really special for our Rocks Box subscribers this month. Each one will get a fossil of Elrathia kingii, the same species that was gathered by the Ute people. Keep it on your shelf, wear it as a necklace.

The choice is yours! If you haven’t subscribed yet, head to Scishow. Rocks to hop on the waiting list.

And watch for some big announcements on more ways to join the club soon. Thanks for watching! [OUTRO]