Rigor mortice is the (temporary) stiffening of joints after death. Animals do not die of rigor mortice.

MORTICE and TENNON

types of frame joints

Joints

A tenon saw is a stiff handsaw used to cut tenons on the end of a bit of wood. It can remove one or two sections of timber leaving a thinner section (a tenon) which is then glued into a mortice (a squared off groove in another bit of wood) making a strong mortice and tenon joint. Framed doors are made this way.