At the First Joint Congress for Evolutionary Biology in Ottawa, Canada, researchers presented information, according to the BBC, showing that the super strong jaw bones and longer canines developed at a time when dog ancestors hunted in groups.
Have there been changes over time? Yes and no. I would not think that a small Maltese mouth could eat a deer rib, but several students of mine have said that their dogs can do this. I also see more (though still not many) broken canines when gnawing on very big bones.
Interesting and I believe that dogs (and cats) are still made to eat bones (raw). I’m cautious about feeding weight-bearing bones (from adult bovine) to my dogs, but they have no problems eating any from deer, pigs, etc. The cats eat whole prey too. They easily crunch through thigh bones of chickens. I don’t typically feed them beef bones because I don’t believe they would naturally eat that and I work to stay as close to species appropriate as possible. Now if one of my boys (dogs) is eating a rack of ribs and one of the cats chews some of what’s left behind, that’s a different story. Of course, I also have large dogs (70lb pit/retrieverX and a 115lb GSD), so they are able to handle the larger bones. I couldn’t imagaine a maltese or shih tzu chomping through a limb bone.