Homo Sapiens Idaltu Gets Kicked Out of the Family

I visited a "Skeleton Museum" recently. It was a large and well-displayed collection of all sorts of bones. Among them were models of the skulls of Cro-Magnons and other hominids. Now you may or may not know that I take a narrower view of what is "human" than those who want to lump all kinds of different species under the "human" label. To me "human" = "Homo Sapiens."  For example, I think the Jebel Irhoud finds from 300,000 years ago are not those of humans, but rather examples of the mysterious Denisovans or what later become Denisovans. Never mind for now the reasons why I believe that, but because I do I thought until my museum trip that the oldest "human" fossils were Omo I and Herto where "Homo Sapiens Idaltu" was recovered. Basically the way Idaltu is named means it is considered a sub-species of our own. And it's dated to 160,000 years ago.

Omo I is said to be the older of the two, if correctly dated, and it was not in this collection, but the Idaltu skull was there, right next to a couple of Cro-Magnon examples, Neanderthal examples, an Erectus and even a sample of Homo floresiensis, the "Hobbit".

Until I walked into this museum, I agreed with the judgement that Homo Sapiens Idaltu was a member of our species, albiet a robust one with hefty brow ridges. It really is surprising how your perception can change between looking at pictures of a skull verses having a three dimensional model in front of you. After getting a close look at those samples side by side, I no longer believe that. Basically the back half of the skull has the globular shape of a modern human and as a result of this the dome of the skull is slightly higher than that of a Neanderthal, even one from over 100,000 years later. The mid-face does not protrude.Those are the parts that look human. The front of the skull however, is very primitive with brow ridges if anything more prominent than Neanderthals. There is a "bone line" from the outside corner of the brow ridge along the skull at an even lower angle than those neanderthal skulls and nothing like the Cro-Magnon skulls. The skull dwarfed those of modern humans in both overall size and robustness.

On the other hand, the Homo floresiensis skull looked a lot like what I would suppose a juvenile Idaltu would look like. That is, reduce the brow ridges and make it smaller and more "child-like" and it would look most similar to the "hobbit" skull. Now you may remember that there was a big dust-up when the "Hobbit" skulls were first discovered because of the claim that they were the skulls of diseased humans, and not that of another species. Over time it was realized that even though the skull had some Sapiens-like features, overall it was too different throughout the whole skeleton to be considered one of us. The hobbit skulls are not over 50K years old and probably much more recent than that. To me they look like a version of Idaltu which suffered from island dwarfism. They too are globular in the back but more primitive in the front of the skull. They too have a fairly small face which does not push forward as much as many hominids but unlike Idaltu, florensis has strong cheek bones.

:LATER EDIT- A recent find fits with Herto/Idultu even better, and that is Homo Longi from China 146,000 years ago. Except for a larger nasal passage- it lived in colder weather - there are a lot of similarities. Could they be regional variations of the same species?

I think what we are finding is that there are many composite hominids. That is they may well have some features consistent with modern humans but lack others. The modern looking feature will vary from find to find. These composites are not the same thing as true transnationals. An El Camino is not "transitional" between a station wagon and a pick-up truck. Its a composite which fully shares features of both, not a vehicle which is halfway between the two in all its features. In the same way a Monkey may have a less-projecting mid-face than a Chimp, but that doesn't mean its closer to us than a chimp. An orangutan may have a higher and less-sloping fore head than a chimp, but that doesn't mean its closer to us than a chimp. The same thing should be considered when we evaluate hominids and their "place in the family".

I am not sure what to make of all of this, but I would like a good look at a model of Omo I. So far I am inclined to say that the so-called Homo-Sapiens Idaltu is not really in the family.