It could have been premature [not that there’s anything inherently wrong with that; as we still haven’t certified that we are the only such creation in existence], if the species had begun its conception and Ascension as the most advanced form of life before the circumnavigation of the globe. At such time it was allowed the concrete recognition and admission that: Yes, this is pretty much all there is here. For now anyhow, prior to plumbing the true depths of the oceans or ploughing through magma to the magnetic center of our sphere [it may often be meant as a collective ecosystem, but really ends up coming to the possessive in the modern technical age; there is no other meaningful entity with which we vie for dominance over the planetary landscape and its resources].
So after that point of being “well-rounded,” we confirmed beyond suspicion what the astronomers had demanded for decades: We are a singular, egg-shaped (faiap) planet, our matron, our captor, our plaything. It was perhaps the first moment at which we could have justly considered ourselves to be a species. Having uncovered any nook and cranny that might have hidden within its unknown recess an evolved lifeform more wise, capable and cruel than Western and Eastern Societies combined.
There was no super-species, no master of dragons that could fell humanity in one sorcerous wave of the hand, or erect pyramids outside of anyone’s observation.
To be truthful, I’m surprised that there were no litany of myths of what we might find west of Westphalia. Perhaps because no one /really/ believed there was even a landmass as large as the American bi-continent. The common assumption was that humanity as a bound and calculated entity had already been explored. It was just a matter of proving it.
But Americas was there, and that spurred a time of new possibilities, and new thinking, and the concretization of the Scientific Method. And once there were no bogey-men hiding in channel locks, things really began to kick into high gear.