From d20srd.org:
Raise Dead wrote:
While the spell closes mortal wounds and repairs lethal damage of most kinds, the body of the creature to be raised must be whole. Otherwise, missing parts are still missing when the creature is brought back to life.
Ressurrection wrote:
This spell functions like raise dead, except that you are able to restore life and complete strength to any deceased creature.
The condition of the remains is not a factor. So long as some small portion of the creature’s body still exists, it can be resurrected, but the portion receiving the spell must have been part of the creature’s body at the time of death. (The remains of a creature hit by a disintegrate spell count as a small portion of its body.)
Edit: Damn you Cory and your ninja training >>