Well, I've finally had a look at the actual Buxton and Rice paper repeatedly cited by Paul and Clyde, and nowhere has Buxton and Rice made any claims that Sumerians were "Australoids" or "Austrics". In fact, Buxton and Rice group the Kish skulls into 3 archetypes, the "Eurafrican", the "Mediterranean", and the "Armenoid". Only the term "Eurafrican" would suggest any tangent connections to the terms "Australoid" and "Austric", but in the context of the paper this term refers to the definition laid out by Haddon, which is descriptive for mainly "Mediterranean" type with suggestive "Negroid" features. This is not to say that the Sumerians have African admixture even, as other evidence suggests sub-Saharan elements only enter the Middle Eastern gene pool en masse much later on, when the region started to entrench a tradition of bringing sub-Saharan slaves prior and especially after the advent of Islamic domination. Instead, certain plesiomorphic qualities of the Kish skulls seems to suggest an autochthonous local stratum still prevalent during the time of Sumer. It is in these particular plesiomorphisms that similarities with Australian aborigines and others (Combe Capelle: Upper Paleolithic Europe; Eskimo) are mentioned, but my knowledge of the overall situation in SW Asia leads me to attribute these archaisms within the Kish and other Sumerian populations to a general pre-Neolithic stratum of the region or specifically a Gulf Oasis stratum, who were not African or "Australoid" despite keeping certain plesiomorphic traits.
Below is the sole characteristics mentioned as similar to Australian aborigines and Eskimos:
They are all long-headed-the cephalic index being often extremely low, and distinctly high (hypsicephalic), the additional height being due not so much to a general increase in cranial height as to a wellmarked scaphocephaly, or keel-shaped, form of the skull. This form of cranial vault is always associated with a great development of the temporal muscles, whose area of insertion is in such cases extremely large, and their upper boundaries reaching in rare cases-, not so far observed in the Kish crania, almost to the middle line. This scaphoid appearance is usually found among people such as the Eskimo or Australian aborigines, who have large powerful jaws and employ them as an efficient implement for triturating rough food. Among the Kish people, however, jaws are small and in no way very different from the jaws of civilized man to-day. The development of the cranial vault is, therefore, all the more remarkable. This remarkable form of skull thus suffers from a lateral compression, producing in some cases remarkably low cephalic indices, those below seventy being not uncommon.
The cranial box itself 'presents a somewhat irregular contour when viewed from above. This condition, recalling, as it does, an elastic envelope, such as a balloon imperfectly inflated, is usually known as " ill-filled." This condition appears to be associated with cranial vaults which have a small internal capacity, but a considerable development of the temporal muscles, and is found typically in such skulls as those of the Australian aboriginals
L. H. Dudley Buxton and D. Talbot Rice. "Report on the Human Remains Found at Kish. The Journal of the Royal Anthropological Institute of Great Britain and Ireland, Vol.61 (Jan. - Jun., 1931), pp. 57-11
1. Penniman's study after Buxton and Rice.
2. Arkadiusz So³tysiak, "Physical Anthropology and the "Summerian Problem""
link 1, link 2