The last person left in the Book of Ether is Coriantumr. This relates to Omni 1:21, which speaks of the people of Zarahemla finding a man named Coriantumr:
And they [a large stone with engravings] gave an account of one Coriantumr, and the slain of his people. And Coriantumr was discovered by the people of Zarahemla; and he dwelt with them for the space of nine moons.
Coriantumr apparently did not die after he cut off Shiz’s head. It only says he collapsed “as if he had no life.” He was exhausted but alive, and it seems that this same Coriantumr is the one who is mentioned as having been found in the book of Omni. He knew his king list; he knew his genealogy. It is possible that certain Nephite names (such as Nehor in Ether 7:4), were first Jaredite names and were passed down by Coriantumr.