A human mandible from the Djalainor Deposit in North Manchuria

Abstract

On September, 1944, the left half of the mandible (No. III) Which is yellowish brown coloured and slightly mineralized, was found at the Djalainor Coal-mine.Dr R. ENDO investigated the vicinity of the Djalainor Coal-mine in cooperation with Dr. W. C. PEI, and found this mandible etc., together with some mammalian fossils and many stone implements.On January, 1945, Dr. ENDO sent to me these human skeletal remains for study.these specimens, Dr. ENDO has already reported. I, therefore, want to present here the results of the measurement of the mandible.In the following table, the measurements of the mandible are given compared with the modern Silingol-Mongolian means published by SHIMA. Although the mandible is absolutely and relatively large, the left third molar does not display yet. The body is high and the teeth are massive. The trace of epiphysial line distinctly remains at the articuiar process (condyle). The mandible is presumably of ayoung male. It gives the moderate development of mental region of the modern type. Three mental foramina are observable. I notice the slight sulcus and fossa mentalis. The torus mandibular is absent. The left five teeth(I2, C, P1, P2, M1)are held in the lower jaw. The occulsal surface is strongly worn out. No pathological symptoms are reckognizable. It has no remarkable archaic character.As the result of morphological examination of three Djalainor materials, I think that the mandible(No. III)may be almost the same antiquity with the skull No. I, and the skull No. II may be older than those of the former specimens.