Pizza Bones

My sister is so much younger than me that our childhoods did not overlap. She just mentioned that she grew up with the term "pizza bones". I knew what she meant (and loved the term) instantly Γ’β¬β I'm curious as to how many others can infer the meaning just from the term. Anyone?
The first thing that came to mind was the uneaten crusts... although these are often dipped in some kind of sauce (as breadsticks are) and eaten.
(And I can hear Bullwinkle answering the question, "Should pizza be eaten with the fingers?" by saying, "No, the fingers should be eaten separately." Just a random thought...)

Right on the button. My sister would throw the uneated crusts to the dog, and so started calling them "bones".
It seems to me that if a term is easy to understand without a lengthy explanation, then it is easier for that term to catch on. You want your listener's reaction to be "I get it," rather than, "What does that mean?" I was curious as to how easily understood this term is - thanks for humoring me.

Very poetic. They do look just like ribs.
I don't know how long I have known them as pizza bones, maybe 30 years? Being raised to clean my plate, I did notice when peers not raised that way left piles of them aside. To me, they looked similar to the discarded piles of chicken bones.
Emmett