A preliminary study of a mammoth molar from the Yellow Sea, Korea

Abstract

Two fragments of mammoth molar were found at shallow marine sediment (water depth of 10~30 m) in the Yellow Sea, Korea. These fossil specimens consist of one and two flat elongated plates about 20 cm in height, 8 cm in width, and 1 cm in thickness. The color of the surface of the plates varies from dark gray to black. Numerous growth lines can be seen in the vertical direction of the height on the surface of the plates. The plates consist of the outer enamel laminae and inner dentin laminae. The enamel laminae are semitranslucent grayish white and harder than the dentin, and the dentin laminae are opaque ivory and less brittle than the enamel. Scanning electron microscopic (SEM) examination of the enamel laminae revealed 5㎛ in diameter enamel rods in rows along the plates and enamel crystals generally oriented parallel to the axis of the rod. X-ray diffraction (XRD) patterns of the enamel and dentin laminae were very clear and similar to each other. This implies that both laminae are composed of hydroxylapatite and were preserved from mineralogical and chemical alterations after deposition. We attempted radiocarbon age dating on the enamel, but it failed to yield a separable protein (collagen). This may be due either to the natural degradation of the protein because of the extreme age of the sample or to low-temperature heating sufficient to burn off the proteins. In previous studies,