The lauburu, literally “four heads” in Basque, is a ubiquitous and ancient Basque symbol. You see it all over the place in the Basque Country and has become a national identifying symbol. It has obvious connections to other four-armed symbols, such as the swastika, a symbol that appears in many parts of the world, including India and North America.
Some how, all of these different cultures came up with very similar symbols. It seems unlikely that they all communicated and shared a common origin for the symbol unless they obtained the symbol before the migrations out of Africa. But, that seems unlikely as well.
One theory, posited by Carl Sagan and others, is that there was a celestial event involving a comet that most of the world could see. As described in this Wikipedia article, depending on the orientation of the comet, an outgasing comet could lead to a pinwheel type structure in the heavens, something many people could have seen, leading to the lauburu and swastika.
Now, there are reports on a massive comet event, occuring about 13,000 years ago, that destroyed a lot of the larger animal life in North America and all over the world. As described in this Guardian article, there is evidence, in the form of nanoscopic diamonds found all over the world, that a comet hit the Earth about 13,000 years ago and profoundly changed the planet, wiping out a number of species, including human populations.
Such an event would surely have registered in the consciousness of humans of the time. And it would have been an event that most people might have seen. And it is a recent-enough event that, once embedded in culture, it could have lasted until modern day.
Of course, this is no proof that the two items — the lauburu and this particular comet event — are connected, but it is intriguing. It certainly makes me wonder.