A more thorough explanation:

Term: de morte antecessoris
Definition: De morte antecessoris is a legal term used in Scots law that refers to the death of an ancestor. It is often used in the brieve of mortancestry, which is similar to the English mort d'ancestor.
Examples: If a person dies without leaving a will, their property will be distributed according to the laws of de morte antecessoris. For example, if a person dies and leaves behind a spouse and children, the spouse will receive one-third of the property and the children will share the remaining two-thirds equally. This illustrates how de morte antecessoris is used to determine how a deceased person's property is distributed among their heirs.