great oxygen event

Unsolved Paleo Mysteries Month #20 – Dubious Diskagma

Only around 0.3-1.8mm long (0.01-0.7″), Diskagma buttoni is known from the Paleoproterozoic of South Africa, dating to a whopping 2.2 billion years ago. These tiny urn-shaped structures were connected into bunches, and were found in rocks that were once ancient soils – hinting that there may have been some form of (relatively) complex life present on dry land much earlier than previously thought, as far back as the early stages of the Great Oxygenation Event.

But what these things actually were is a mystery. Their size and complexity resemble some sort of eukaryote, which would make them one of the oldest known representatives. They also have some similarities to the older fossil Thucomyces lichenoides, the younger fossil Horodyskia, and a modern fungus with internal symbiotic cyanobacteria.

Or they could be a very early “experimental” branch of life with no close living relatives. For now, we just don’t know.

Of course there’s no aliens on Earth

I mean sure, theoretically, aliens could have noticed any time from the Great Oxygenation Event 2.3 billion years ago onwards that life was probably happening here, which might be reason enough to investigate, and sure, in principle, if there were aliens who were significantly longer lived than us, visiting more-or-less nearby places around the galaxy might be a very possible thing to do even with, yknow, currently-known-possible-by-earthlings technology; 

And sure, hypothetically, given a few thousands or maybe millions of years head-start in technical development, they would probably find it easy to, like, biosynthesize human or other animal bodies to drive around and explore this weird rock, and sure, it’s possible that some of them might have come here with weird ideas about what are better or worse ways of arranging this world that have nothing to do with the views of its current inhabitants, and i mean sure, in principle, those who wouldn’t have come with those ideas would be really really sorry about what those other people did.

But there’s no aliens on Earth, people! You do not need to suspect anyone of being a nearly immortal alien! Such people cannot be found on Earth and do not need to be searched for!