I want to post this before I forget (and before someone else claims it). I think that we should preemptively add a "top" level to our classification/cladistics/phylogeny. It's tentatively a "super-superregnum" level, which puts lifeforms into entire biologies based on their planets (or other regions) of origin. I think that ours should be called "Terrus" because it sounds like "Terran" but "Terran" is already used descriptively in other ways, and because most of these end in "-us" or "-um".
I also hold that one super-superregnum (such as "Terrus") could in fact cover multiple planet, in cases of panspermia, whereby one planet's (or other region's) biology originates from another's.