How to tell H. neanderthalensis from H. sapiens sapiens

An everyday question we all come across at some point - let’s say I take a handful of Neanderthals and a handful of anatomically modern humans, both from circa 50,000 B.C. Unfortunately they’re all mixed up and I don’t know which is which.

Trouble is, I’ve fallen out with the guy who runs the DNA tests since the results of that paternity suit. Sans genetic evidence, is there any cast-iron bulletproof way of sorting the two species? Something that sapiens can do but neanderthalensis can’t or vice-versa? I also don’t want to kill any of them (would cause a time paradox) so autopsies are out, but would any sort medical examination reveal the truth 100% of the time?

The best I’ve got based on background knowledge is that the Neanderthals are going to be a bit stockier and have a more prominent brow ridge, but it seems a bit subjective. Whadya reckon?

Here are some of the differences in the skulls of the two. In particular, the skulls are quite differently shaped, with Neanderthals having an “occipital bun” at the back of the skull.

There are also differences in the rest of the skeleton.

You could determine the difference in bone structure externally; you wouldn’t have to do an autopsy or probably even an X-ray. I am not sure that any one character is diagnostic (the occipital bun may be) but taken together I think there would be much less problem distinguishing a Neanderthal from a modern human than an Eskimo and a Masai.

Very pronounced brow ridges.

No chin.

A face that was as if someone had grabbed the front of yours and pulled it out a couple inches.

Forehead that slopes back a bit above the eye sockets instead of being vertical.

You really think so? I can’t imagine getting even one wrong answer when asked to tell an (adult) eskimo from a Masai out of say, 50 of each. I would not bet on getting 100% correct for 50 Sapiens vs 50 Neanderthals. I think I might mischaracterize one or two of the Sapiens, even if I got all the Neanderthals right.

I think you underestimate the distinctiveness of Neanderthals when all characters are considered together. I have trouble imaging you would misclassify a single sapiens as a classic Neanderthal if you had the individuals in front of you, or even a complete skeleton.

I suppose we don’t really know how much individual variation there was in the Neanderthal physiognomy–eg some Sapiens have receding chins, so maybe some N.s had prominent ones–but I don’t see how you could miss the shape of the skull. Maybe if the individual had lots of hair and you were not permitted to get to close, or feel the head, but if you sufficiently limit the amount of imaginary examination you’re permitted in this thought experiment, of course the imaginary you will make some wrong guesses.

Time to dust off the old phrenology kit?

What about the juveniles? Should mention that the question was inspired by this fascinating site of facial reconstructions and the thought that if push came to shove I wouldn’t be 100% confident of being able to say who’s a Neanderthal and who’s not.

Would tool use be a pointer? I’ve heard that one of the possible factors in Neanderthal extinction is our fore-bearers being able to master the throwing spear, whereas Neanderthals seemed to prefer things up close and personal. Are there any other examples? Music, maybe?

You see the larger joints on the Neanderthal skeleton? That means the muscles are corresponding larger as well. Neanderthals are very heavily built. They are, literally, big-boned.

Only Neanderthals had a suprainiac fossa, which is a depression above the occipital bone. More importantly, they appear very early in development so you could use them to identify juvenile skeletons too.

There are superficially similar features on some modern human skulls but AIUI those are distinguishable.

Given that Neanderthals are believed to be lighter in skin and hair than the Masai (closer to Europeans than Africans) you probably wouldn’t have any trouble sorting Neanderthals from the dark skinned Africans. Distinguishing them from Asians and indigenous folks from the Americas probably won’t be much of a trick, either. It’s Europeans they might get mixed up with, which isn’t entirely surprising given that there is some evidence of Europeans being part Neanderthal (a very, very small part, by the way, about 2-4%) and both groups probably adapted somewhat to local conditions in similar ways.

If you can use x-rays the determination is pretty straight forward given skeletal differences, but as noted, these differences are visible to the naked eye. Neanderthals don’t have “receding” chins by our standards, they don’t have chins at all. Their brow - the space between their eyebrows and the top of their skull - is about half that of a Sapiens. These differences would be apparent even with modern clothing and grooming.

I’ve spent a lot of time looking at Neanderthal bones and, more importantly, Neanderthal recreations, so I’m just gauging by that. You could be right, but I’m just going by my own experience, and having seen some pretty Neanderthal-ish sapiens walking the streets. Not all of us have chins (or much of one), and some of us have some heavily protruding faces.

You’ve been to Norfolk, then?

Right, but I don’t think you’d find a modern human with ALL the Neanderthal facial characteristics–and none of them would have the elongated skull.

I spent a little time googling–totally scientifically!–and what struck me was that no matter what the facial features we’ve all got that rounded skull.

I believe 50,000 years ago, humans were all Africans.

What about these two: 1, 2 ? One is a model of a Neanderthal and the other is a former heavyweight boxing world champion.

Googling reveals that the first evidence we have of H. sapiens sapiens in Europe is about 45,000 years old, before that it seems that we could have been knocking about the Middle East up to 125,000 years ago (!).

In my opinion it’s also highly likely that Neandertals would look very different from us, not just because their skeletons were different, but because they had different skin and hair and other soft tissue. If you had to tell the difference between and lion and a tiger just by the skeleton it would be difficult unless you’re an expert. If you could see the specimens live it would be extremely easy.

Closely related primate species often have distinctive hair and skin patches so that it’s easy to tell them apart.

So it seems likely to me that Neandertals had distinctive noses, or ears, or mouths, or eyebrows, or hair textures, or beards, or mustaches, or crests, or skin tones not found in modern humans, or hair colors not found in modern humans, or secondary sexual characteristics, or other features many standard deviations away from the the range found in anatomically modern humans. This isn’t even taking into account easily observable behavioral differences.

There’s no particular reason to suspect any particular exotic phenotype for Neandertals, but there’s very good reason to suspect some kind of exotic phenotypic difference, just because closely related species almost always have several things of that sort that differentiates them.

Look at his prominent chin, though.

But notice that your hyper-robust Homo sapiens sapiens specimen has a gigantic protruding chin, and a very short skull. Take a look at this side view:

No Neandertal would have such a brachycephalic skull, or a chin like that. And that guy’s gigantic nose? Puny for a Neandertal. He does have some impressive brow ridges for a Homo s. s., I’ll give you that.

And, of course, the answer is going to depend on whether the person doing the selecting is someone like Colibi who does this sort of thing for a living or of he’s the “man on the street”, who has some vague idea of what a “Caveman” looks like. Not sure where on that scale our OP falls.