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If you choose these as a weapon for your tyrant, do you still recive the +1 attack for having two CC weapons? The codex says they take up one weapon choice.
Under the scything Talons entry it stats that scything talons are "the only way Tyranids gain extra attacks in close combat for multiple weapons"
Therefore Bonesword + Laswhip would not give you +1 attack.
Ok, thanks for the clear up.