Thanks for this and for all your recent activity on the forum.
I see what you mean, but I can't tell if those holes were part of the animal or if they were made after its death. To me it still looks more like a shell fragment. I said Limpet, but it could also be a type of bivalve. I really don't know, but I can't see it as a seaweed.
You're very welcome.
I only started answering questions on NaturePlus because it seemed impertinent to ask a question without giving something back. Oh, BTW, nobody has answered my question
Please could we have photos of:
- the other sides of your specimen
- the same side, but wet (wetting often makes subtle structures more obvious)