Is this a shell?

[paul monfils]

It's a "shell" in the broad sense, but not a mollusk shell.  This is a "test" ("shell") of a heart urchin, an echinoderm, a phylum of animals that also includes sea urchins and sea stars.  In life it was covered with small slender spines which made it look "fuzzy" or "velvety".  I don't have much expertise regarding species of this group, but I think it may be this one:

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