realm

Major regions (kingdoms and realms) are still determined as those that have the most endemics or, stated another way, those that share the fewest taxa with other regions. As regions are further broken down into subdivisions, they will contain fewer unique taxa.

…them to higher units called realms, equal to the remaining regions combined. Such a scheme presents the following realms: Neogea (Neotropical); Notogea (Australian); Metagea (Holarctic, Oriental, and Ethiopian); and Antarctica.