What key skeletal feature allows a cat to pass its entire body through an opening if its head fits?

Answer

The floating clavicle, which lacks a bony attachment

The floating clavicle is an adaptation that is not connected by bone to the rest of the skeleton. This enables the cat to compress its shoulders and squeeze through narrow spaces.

What key skeletal feature allows a cat to pass its entire body through an opening if its head fits?
anatomyÇatbodyFeatureanimal