how flexible were trilobite exoskeletons? i look at groups like Odontopleurida and wonder how often their crazy long spikes got stuck on stuff.
I haven't seen much to suggest that their spines were particularly more flexible than spines on modern arthropods, but I'm not a paleontologist so it's totally plausible to me that there's some mechanism to make it happen that they're still teasing apart. If they were flexible, though, it doesn't seem like the range of motion was huge--my understanding is that the variation in relative spine position in fossils from a given trilobite species isn't notably large, even in situations where it seems warranted, like enrolment (enrolled trilobites with long genal spines look INCREDIBLY goofy).