In The Garden: can anyone identify this fruit

Can anyone identify this fruit

 

I think it is Pouteria sapota, mamey sapote.

 

Mamey sapote have 5 seeds, though. I'd place bets that it is a sapote, just not that one.

 

I've only ever seen one of these before. I bought one in Mexico, but unfortunately it was not a good one.

According to this site they have one or more seeds, so apparently all five carpers don't always fill.
http://www.hort.purdue.edu/newcrop/1492/sapote.html

 

Hm. Here, the five carpers are always full. Maybe it's because I'm in the native range, and we have the appropriate pollinator (whatever that might be).

 

This fruit only had one seed in it. it was given to us by a relative who had just come back from south America. We tried eating it raw but was very bitter. So my mom tried baking it. that didn't work to well either.

 

If it was very bitter, it wasn't a Mamey. Black Sapote, maybe, but Mamey are very sweet fruits (I can tell you from experience, as they're one of my favourites when they're in season.)