The basic idea about Atlanteans follows the theories of Lewis Spence: the Atlanteans were actually Cro-Magnons. However, there is not really reason to say they must be NATIVES of Atlantis if the point is that Cro-Magnons from Europe crossed a series of "Stepping-stone" islands to reach America during the Solutrean period. There are good reasons for the construction that includes Mitochondrial DNA haplogroup X in this migration: however, of the haplogroups found in the Americas, A, B, C, D and X, what may NOT be immediately apparent is that A and B are mnot closely related to C and D-they are more closely related to X. Therefore it is not unlikely that the Solutreans that made the crossing included As and possibly some Bs along with the Xes. Both As and Bs are not common in East Asia and in fact some of their populations IN Eastern Asia evidently have come from America and crossed the Bering straits the other way around.
CroMagnon Reconstructions by R. R. Gerasimov, a respected leader in the field of Forensic reconstruction work.
European CroMagnons actually show significant differences from later Europeans in general and the range of variation in their skulls covers several different sorts of Native American types. In particular, there is a larger, ruggeder type of peoples native to the Eastern Woodlands area and then again in the temperate zone of South America, and it has a smaller-sized and slighter, more "Civilised" variant in warmer regions-South of the Eastern US but more to the Tropics of South America. The taller ones with ruggeder skulls correspond to the Iroquoians and Lenapids of North America and to the normal Patagonians, while the smaller version is more like the Archaic shell-mounds people of the USA and tha Arawaks in the Amazon area and the Antilles. Both the larger and smaller types are very close to European CroMagnons and NOT to any of the people more typical of the Orient. Furthermore, these same CroMagnons tended to have certain features, such as shovelled incisors and enlarged pulp cavities within their molars, which are more like the Americans and LESS like modern Europeans.
There has been a lot of talk about Kennewick Man and how his skull is supposed to present an unusually European-like appearance and different from other comparable Paleoindian remains. In point of fact, Kennewick Man and Spirit Cave man are rather typical of the Paleoindians, who in turn tended to resemble CroMagnons of Europe much more strongly than some of the later waves of Asiatic settlers that came after them.