What were these?

[siege]

Found while rip-cleaning the sand I got...



Anyone have any idea what either sets of things are?

I'm especially interested in the things in the middle. I threw the first one or two I found to the side, thinking it was just a chip off of something, and then after I found a few more realized it was a... thing, of some sort. Almost tooth-like, but reasonably certain that's not what it is. They're about 15mm in length or so - which should give a scale for the round things.

 

[myvwrock]

Well the outside ones were definitely snails. It looks like the middles might fit together like a crab leg just a hunch

 

[siege]

Well the outside ones were definitely snails. It looks like the middles might fit together like a crab leg just a hunch

Definitely looks like a snail of some kind... but... flat??? And there's no hollow part? There were quite a few of those.

As for the other, I don't think so? These things are hard and stony, and there were more than a few, all this same size and shape.

 

[John Bowers]

The outer two are the "door" of turbo snails it is called an operculum. They can close up if necessary. The center is broken fragments maybe from a clam or snail it might have been part of the live rock and broke off based on how beat up it looks.

 

[jcook54]

You'll see all kinds of snail "doors" if you keep an eye out. Some of them look like fish scales and other look just like what you got there.

 

[willwoo]

Yep the outer two are definitely snail opercula. I’d be willing to bed the middle blade-shaped ones are some species of conch opercula.

 

[siege]

Yep the outer two are definitely snail opercula. I’d be willing to bed the middle blade-shaped ones are some species of conch opercula.

Those being the small stony bit attached by muscle/whatever to a larger, less resilient organic structure like that makes sense.

 

[CherylG]

I had a large urchin die and as I was taking it out, flat things fell out of the teste that look like the things in the middle

 

[siege]

I had a large urchin die and as I was taking it out, flat things fell out of the teste that look like the things in the middle

By Triton I think you've got it! There were quite a few pieces of urchin tests mixed in the sand, and looking at urchin anatomy, it looks very much like these might be part of "Aristotle's Lantern":

 

[Jikkermanccini]

The middle pieces look like conch opercula, which are blade-like. Not symmetrical enough to be urchin teeth, though I wouldn't be shocked if you do end up finding some in the sand too.

 

[siege]

The middle pieces look like conch opercula, which are blade-like. Not symmetrical enough to be urchin teeth, though I wouldn't be shocked if you do end up finding some in the sand too.

You're not wrong either, looking at the photos of conch anatomy, that's a very solid contender, and IIRC I'm pretty sure there were a few conch shells I pulled from the sand.