How to combine animations from 2 different dinos

I’m making a chimera (putting the head of a dino on the body of another) which is easy enough for the skeletal mesh.

My question is how do I do the same for the animations? I tried attaching the armatures of each animation to each other like I did with the skeletal mesh however when I do the animation that has the child bone loses its actions, ie attaching the head to the body causes the head to no longer have an animation.

Can someone please help me with this? Im using blender to import and edit the fbx files