individual layer data lost and illustration is grouped onto a new layer

[taco salad]

I copied a complex illustration that had many layers into a new document. Now the origianl illustration has everything grouped onto a new layer and the origianl individual layers are empty. What happened? and what can I do to get the original illustration back?

[Jacob Bugge]

taco salad,

I doubt whether it is possible, but have you tried a simple Undo in the original document (you probably have)?