Quote from Laskeri
Skeleton and Zombie Skulls can be found in Thaumcraft villager houses.
By the way, is anyone else having an issue where Mana Beans have no effect whatsoever? They don't give me a potion effect, and don't give me any research points. This is with Thaumcraft 4.0.4c, Thaumic Tinkerer 2b26, and Forge 939. I can post the rest of my mods if needed.
Forge 916 is still the recommended build. For good reason. I know mystcraft 1.0.11 requires 938+ but Ive seen so many 'bug reports' resolved to using 'non recommended forge builds that its just not worth it.