Help me identify this sea creature

I expect so - they should look something like this when they’re alive:

Looks like either the top surface of these specimens has shrivelled, pulling the mantle up and around, or the soft body parts have swollen.

Nope, it’s right side out.

Ah. Are the plates internal in the gumboot chiton? (I thought they were on the back like other species). In that case, are we looking at the internal plates up through the (emptied) body cavity?

Must be. Whenever I’ve seen them undewater, they look like the photos- pinkish orangey, and soft and rubberlike.

What species are those? They appear not to be gumboot chitons.

While I don’t have personal experience with the species, sources indicate that the gumboot chiton is unusual in that the mantle normally covers the back plates, as shown in the pictures previously linked to. In most other chitons, the plates are exposed.

It looks like my image search misleaded me - I didn’t realise the gumboot chiton’s plates are internal.

So it looks like the OP’s pictures consist of the remains of one from which the internal organs are missing.

Fascinating. Thanks!

Should be noted that everything past the first sentence in that quoted post is incorrect, ShadowFacts - due to my misunderstanding of the anatomy of this organism. The magnetic teeth thing is, as far as I can tell, correct.

I immediately identified it as a chiton, we have them in our area.

Don’t know which species though.

Don’t be too hard on yourself- you describe other species of chiton in that quote, just not this particular one.