///Category tree for species similar to earth mammals
User:SOTO/Forum Archive/The Panopticon/@comment-24894325-20170117192114 These seem to be used improperly used as a matter of course. On the other hand, I like the way they are used. So I would change the tree of categories. Here is a problem: look at the following branch of categories from smaller to larger:
Category:Dogs -> Category:Canids -> Category:Earth predators and Category:Earth mammals
So dogs can, therefore, contain only animals of the Earth species dog. But there are many dog-like animals from other planets, completely unrelated to dogs. And it's completely natural to use Category:Dogs for them, and many editors do. For instance, in this category, we can find Parzival of the species Vegracandis, Barcelonian dog from planet Barcelona, Howzi from Trenzalore, etc.
And if we go to a less specific category name, like Category:Canids, we get a whole subcategory Category:Sentient canines, mostly inhabited by residents of Dog World.
My proposition is to acknowledge status quo by moving categories "Dogs", "Canids", and many others to Category:Predators instead of Category:Earth predators. If enough members exist, subcategories such as Category:Earth dogs may be created.