their bones that connect the left and right side are not connected like a cat which allows their shoulders to collapse so they can squeeze into tiny spaces. Our bones would break. ouch! Collar bone. read more
Yes, mice, rats, and frogs all have ribcages. I have done dissections to all of them. Not sure about salamanders, but basically I think anything with a true heart has a ribcage, sicne they are designed to protect the heart. read more