I ALWAYS forget the name of these little guys even though I see them pretty frequently. Thank you for the reminder... I'll try to commit it to memory this time (no promises)

[–] DarkThoughts@fedia.io 4 points 2 months ago (1 children)

It's certainly not a spiral thread, but individual rings, which aren't even uniform enough if they were a thread of a bolt or a screw.

[–] FlyingSquid@lemmy.world 8 points 2 months ago (1 children)

There is no question in my mind that it's a crinoid. I grew up in a town in Southern Indiana that was essentially a giant crinoid bed in the Cambrian. I had so many pieces of crinoid. I even had a "flower," which were really hard to find. Sadly, I lost it.

Here's a bunch of "stems":

Here's a "flower":

I put those words in quotes, because a crinoid is actually an animal, not a plant. Here's a sea lily, one of its modern descendents.

[–] acetanilide@lemmy.world 2 points 2 months ago

I had no idea those were animals. Fascinating.