The first hypothesis, proposed in 1925, was the one that would become the most famous and the most contested: the suggestion that the Punín-1 skull showed evidence of Oceanic ancestry. Specifically, that the skull’s physical features — including those prominent brow ridges and other morphological characteristics — resembled skulls from Australia and the Pacific Islands, and that this resemblance was evidence of ancient contact between the ancestors of the people who would become the indigenous populations of South America and the peoples of the Pacific.
The second hypothesis, more extreme, followed from the apparent geological age of the skull: if the sediment was genuinely Pleistocene in age, and if the skull was genuinely from that sediment layer, then the skull might predate modern humans entirely. This prompted speculation about whether the remains could belong to a now-extinct relative of modern humans — Homo erectus, which had existed in Asia until roughly 110,000 to 117,000 years ago, or even Neanderthals, though the geography made the latter extremely implausible.
These were spectacular claims. And spectacular claims attract sustained scrutiny.