Trilobytes did use a defensive posture like a Rolly Polly/Wood Shrimp/Penny Sows after all.

 

Found these on Ebay of all places. Bunch of fossils for sale, this was like $235 in May 2024. 

Here's more, and this species looks / reminds me of Giger's Spacejockey in Alien again: 

Speaking of Rolly Pollies, they can sort of get rid of bad metals like lead by crystalizing them in their body. Incredible! Just learned this:

https://www.treehugger.com/roly-poly-pill-bug-facts-important-environment-4864410

Quote:
7. They Eat Metals

Roly-polies play important roles in the environment. They are able to take in heavy metals such as copper, zinc, and lead, and then crystallize them in their bodies. This has made them an ideal test subject in studies of pollution and related environmental research.3 The pill bugs’ unique ability to remove heavy metal ions from contaminated soil allows them to thrive in polluted locations where other species cannot.4 

So many names:

"most common species is Armadillidium vulgare, and they are officially called pill bugs, but they’re also known as doodle bugs, wood shrimp, and woodlice. People in the United Kingdom refer to them as chiggypigs, penny sows, and cheesybugs"

View Article Sources

Potter, Michael F. "Sowbugs and Pillbugs." Entomology at the University of Kentucky.

Holland, Asa. "Armadillidium vulgare: Pillbug." Animal Diversity Web.

Szlavecz, Katalin, et al. "Terrestrial Isopods in Urban Environments: An Overview." Zookeys, vol. 801, 2018, pp. 97-126., doi:10.3897/zookeys.801.29580

"Pill Woodlouse." Encyclopedia of Life.

Edney, E.B. "Transition from Water to Land in Isopod Crustaceans." American Zoologist. 1968.