User blog comment:ImperiexSeed/Supernatural Mysteries/@comment-3481504-20130307031256/@comment-5619706-20130307165705

It's not a stretch that they could have preyed on each other, especially since no other creatures were alive at that point. So I think I agree with Ensephylon. There is a chance they could live in space, them being indestructible and capable of regeneration. Then again, maybe there was a proto-earth. Or maybe that proto-earth was purgatory itself (since it looks primeval anyway), and God simply sealed it away and merely fashioned a new earth, instead of the earth being made first then purgatory made after.