摘要：Five skeletal remains of epi-Jomon and pre-Okhotsk period (approx. earlier half of the first millennium A. D.), excavated in 1959 from the Onkoromanai shell-mound near the Cape of Soya by Prof. S. Izumi and his staff of Tokyo University, were measured (see Table) and described.The major anthropological characteristics of these remains were : 1) mesocrany, with indices higher than the recent Hokkaido Ainu, 2) hypsicrany, in contrast to the orthocrany of recent Ainu, 3) longer frontal arc than the Ainu, 4) strongly bulging glabella, deeply subsiding nasion, and projecting nasal bones, as are common in the Ainu, 5) extremely low and wide face, 6) rectangular and very low orbit, 7) narrow nose compared to the breadth of the face, 8) coincidence of straight (nonainoid) and rounded (ainoid) lower margins of the mandible, 9) broad ramus and everting angle, 10) relatively long radius and tibia, and 11) flatness of long bones, with the exception of the femur, of which upper part of the shaft showed no flattening and middle part showed pilaster formation, as is usual among Japanese Jomon period femora.In these features, especially in 4, 5, 6 and 10, the Onkoromanai type was quite distinct from the Okhotsk-type such as found in Moyoro and Omisaki. On the other hand, it had much in common with the Ainu and the Japanese Jomon-type. The ainoid (4, 5, 6 and 10) and Jomon-type (1, 3, 4, 5, 10, 11) features were compounded in these skeletons. But the former was stronger rather than the latter. These results of comparisons seemed to suggest that the Onkoromanai type represented at least one of the ancestral forms of the Ainu race.When compared with the three major local types of the recent Ainu, i. e. of Hokkaido, Sakhalin, and Kuril, the closest resemblance was found to the Kuril Ainu of Shumshu Island. In order to illustrate the relative degree of affinity, the craniometric deviations of the Onkoromanai (2 males and 1 female) from the means of the Hokkaido Ainu (Yakumo cemetery in Southern Hokkaido, by WATANABE, 1938) were shown in Fig. 2, together with those of the Kuril Ainu (from Shumshu by KODAMA, 1940), Tsukumo (shell-mound of Jomon period in Japan by KIMONO & MIYAMOTO, 1926), Sakhalin Ainu (from Rorei cemetery of eastern coast by HIRAI, 1927), and Moyoro I (typical Okhotsk type from Moyoro shell-mound in Eastern Hokkaido by ITO, 1948).The remarkable resemblance between the Onkoromanai and the Kuril Ainu, as seen in Fig. 2, led the author to assume that the marginal Northern Kuril Islanders might be a survival of the ancestral form of the Ainu.
