[1] Although a secondary wife, Lady Ikʼ Skull may have ruled for a short time in Yaxchilan's history until her son Yaxun Bʼalam IV was old enough to take the throne.

[4] There is a great deal of speculation as to why the son of a secondary wife took the throne and did so after the king had been dead for ten years.

The current thinking is that the rightful heir through Lady Xook's lineage may have been her son, or perhaps a nephew or brother,[5] but that this individual was captured during a conflict with Dos Pilas in 745.

In their second revised edition, Martin and Grube note that at Piedras Negras there is mention of a new king at Yaxchilan, Yopaat Bahlam II, who may have ruled for part or all of this period.

On the other hand, Josserand notes that Lady Ikʼ Skull ruled as regent during this time and that it was not until her death that Bird Jaguar IV took the throne.