Of all the 337 names mentioned in the Book of Mormon, not one has a surname. This is consistent with the Bible but in direct contrast to Joseph Smith’s immediate surroundings. If Joseph was simply influenced by the world around him, we might reasonably expect him to have gotten this wrong.
Donald Parry comments:
Had Joseph Smith authored the Book of Mormon in an attempt to pass it off as an ancient record, he might easily have slipped up by giving at least a few of his characters surnames, as was the custom for centuries before the coming forth of the Book of Mormon.– Donald Parry – Echoes and Evidences of the Book of Mormon
How did Joseph manage to escape this easy error?