I was reading Plutarch's Life of Theseus when I came upon this passage that to me describes so-called Neanderthal man (who was a human). For context, Theseus has just come of age and is going to Athens, but his mother and grandmother and others implore him to go by sea because the land is infested with robbers and bad men. So Theseus decides to go by land because he wants to emulate Heracles. Now here is Plutarch's description of the men who inhabit the land and who cause all kinds of trouble. Notice they are humans:
"For it was at that time very dangerous to go by land on the road to Athens, no part of it being free from robbers and murderers. That age produced a sort of men, in force of hand, and swiftness of foot, and strength of body, excelling the ordinary rate, and wholly incapable of fatigue; making use, however, of these gifts of nature to no good or profitable purpose for mankind, but rejoicing and priding themselves in insolence, and taking the benefit of their superior strength in the exercise of inhumanity and cruelty, and in seizing, forcing, and committing all manner of outrages upon everything that fell into their hands; all respect for others, all justice, they thought, all equity and humanity, though naturally lauded by common people, either out of want of courage to commit injuries or fear to receive them, yet no way concerned those who were strong enough to win for themselves. Some of these, Hercules destroyed and cut off in his passage through these countries, but some, escaping his notice while he was passing by, fled and hid themselves, or else were spared by him in contempt of their abject submission..."
I will be submitting my research to the peer-reviewed Journal of Finding Obvious Things that are Obviously True.