These look like bits of shells.

Ilymatogyra Arietina bivalve maybe

I think it’s limestone & it looks like an Orthocone. A Cephalopod. 🦑

Migratory rocks are just part of the rock cycle. They come from around the world and end up on beaches sometimes with similar friends around them, sometimes all alone.

I’d really like to find a definitive answer for this specimen. It has been bugging me for a while now. The specimen post to the right of this post is also mine, and these were collected as as side-by-side. Take a look.

I was wondering if it was some kind of stromatolite.

I’ve also have never seen space between stalagmite growth rings, I looked online and could not find any examples.

Sorry for the typos, small chat box..

Idon’t think so. It was a feature of an Mississippian fossil reef. The vertical lines do not match stalagmite growth rings. Though the exterior looks very similar. Smithville,TN has an abundance of marine fossils and this was collected alongside a great many specimen species. Sponges, brachia, pods, and crinoids. We’re all collected within 1 foo…[Read more]

They look Cenozoic.

Why are you posting museum specimens here? This is a fossil identification form.

Share this photo with other forums. I’ve never seen anything like this. It looks like Ordovician rock, but might be a new species. Share as much info about it as possible. Post on Facebook fossil forms & inaturalist.

Squid indeed.

Rugose indeed. (Horn coral)

Coral / Bryozoa

Definitely looks like bone, what environment was found in?

Very cool!

I suppose it could be. Yet there is some kind of chaotic symmetry going on here.