dwarf or juvenile ?

[paul monfils]

Well, that's a good point. If it were an adult dwarf, I suppose it might retain the protoconch the same way a juvenile does, at least for a while. But this specimen definitely has a juvenile look to it, its apparent thickness and weight, plus the well formed protoconch.  An adult dwarf, in a photograph, without a size reference, would look virtually identical to a large adult shell. This one doesn't.