This marker (Monument 69) was recovered from the centre of the Ball Court #1 at Toniná. It is now on display in the Regional Museum at Tuxtla Gutierrez. Its text references the death of lord Wak Chan K'ak who was (possibly) heir to the throne at Toniná. He died September 5, 775 CE without having achieved power. His body was entombed 260 days later, May 22, 776 CE. The work is from the Late Classic era.
The marker rested atop an offering hole, that is still there (covered of course) today. If you look carefully at the sceptre bar pressed to his chest, you will note that the ends do not terminate in the usual serpent image. Instead, this image has been replaced by a glyph for the white-flower-soul. He clutches the ecliptic path to the Otherworld through the Ball Court with a symbol of his very soul.