"who figured out that you could use rocks to bust open bones."
Most carnivores use their teeth to crush bones - lions and hyenas both do it. Heck, we buy doggie treats related to marrow and I have watched my own dogs crush bones to get to the marrow.
Marrow is quite accessible to all, including me - omnomnomnomnom.
Just to clarify, chicken bones themselves aren't a huge issue. It's cooked chicken bones, actually any cooked bones at all, that splinter and cause problems.
Of course, birds have small bones so dogs can conceivably choke on them when uncooked as well, but it's generally not a huge concern. The splintering however, is a result of cooking[1].
I have a chicken in the slow cooker almost every single day. If the bones have cooked for more than 12 hours, it’s not possible for them to harm anyone. They’re too soft. By the time is they have simmered 24 hours, they are easily chewable.
Most carnivores use their teeth to crush bones - lions and hyenas both do it. Heck, we buy doggie treats related to marrow and I have watched my own dogs crush bones to get to the marrow.
Marrow is quite accessible to all, including me - omnomnomnomnom.