Aliens on Earth -- Part 2: Revisions

In the last post, I covered the aliens in H. P. Lovecraft's solo work. Moving to his revisions and co-authored stories, the picture gets muddier.

In "The Mound" a race of humans or semi-humans is found in vast caverns under Arizona. Despite their human appearance, though, they claim to have been brought to Earth by Cthulhu. Even they have begun to doubt it at this late date, but they do have strange idols of a metal not found on Earth to back up their beliefs. The rest of humanity is descended from them, and their history seems to cover a vastly greater span of time than that of surface humans - "they knew of the outer world, and were indeed the original stock who had peopled it as soon as its crust was fit to live on." If taken literally, this would mean that their species is billions of years old. I frankly don't think this can be harmonized with Lovecraft's other writings: it seems like they would have shown up in the histories of the Yithians or Elder Things, not to mention all the references to "pre-human" this, that, or the other. It can work, though, if we take "as soon as its crust was fit to live upon" as hyperbole, putting their arrival on Earth sometime in the late Cenozoic (though it might have to be earlier, if they were in fact brought by Cthulhu; the geological period of R'lyeh's sinking is unclear).

In "Out of the Aeons", Ghatanothoa is the god of a race from Yuggoth (that is, Pluto) that came to Earth "before the birth of terrestrial life" and built great cities and fortresses, but then died out. Ghatanothoa, apparently being immortal, is the only survivor, but he may not actually be of that race. It seems that this species is not the Mi-Go/Fungi from Yuggoth from "The Whisperer in Darkness", since the Mi-Go seem to have arrived later in Earth's history, and "The Whisperer in Darkness" says that Yuggoth was once inhabited by another species before the Mi-Go arrived. We are not told why this species settled Earth; but if they were natives of Pluto, Earth would not be far away.

"The Challenge from Beyond" describes a cube used for mental transmissions and transfers by the centipede-like Yekubians; but these had no special interest in Earth until they struck it by accident, having scattered the cubes across all of space where they would hopefully land upon inhabited worlds. Later they made mental contact with the Yithians, and Earth became more interesting to them.

So, in summary: The only species whose reasons to choose Earth are uncertain are the Elder Things, earlier Yuggoth creatures, and Yithians: and all of these have credible reasons. The excessive number of species doesn't seem so excessive after all...