Haven't found any ribcages, but I've found a good handful of skulls around.
Big ones, small ones. In the ground, in the air.
Nothing happens when I hit them- no damage numbers, no "too hard", not even a swarm of bugs like everyone else is complaining about.
https://cdn.discordapp.com/attachments/474550289181966336/1050623466455445535/20221208211539_1.jpg