I was checking the the
Animal Skull heads and this seem to have more texture options than the Skeleton Skull, skeleton Torso,waist,arm & legs.
All Animal skulls have access to
Holoforce, Psionic and
Glass textures
While Skeleton skull and the rest of the skeleton parts don't. I really don't know if there's any technicality involved but, if possible, would like to have those textures available on the rest of the skeleton parts