Native pottery fragments coconut?

Description

I’m not sure if this is a cup made of pottery or an actual coconut made into a bowl. I got it from a yard sale and thought it interesting. Looks like you could mostly resemble it. Seems to be very old and if it’s a coconut, it’s nearly petrified. If it could be carbon dated, that would be interesting to know and possibly its origin.
Thanks for looking!
Fordham’s Odds & Ends, Antiques & Collectibles