長鼻類の歯の走査型電子顕微鏡による観察

概要

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Proboscidean Research Group is making systematic and synthetic studies of the elephant molar teeth from the microscopic to macroscopic level. In this paper the author made scanning electron microscopic observations of molars of four elephant species; Elephas indicus (Elephas miximus), Loxodonta africanus (Elephas africanus), Elephas namadicus naumanni MAKIYAMA (Elephas naumanni MAKIYAMA) and Elephas primigenius (Mammuthus primigenius). Each specimen is polished along three axes of the molar. The enamel was divided into three layers: first, middle and deep. The middle layer was where Shreger bands were observed. At the horizontal section of the molar, most of the enamel of the middle layer revealed a "frond of the maiden hair fern" pattern, as pointed out by MUMMERY (1924). From this observation, it was deduced that this prism pattern was common in three species of Elephas out of the four (except Loxodonta africanus). At other layers, the first and deep, a few other patterns were also observed. In the dentine of fossil elephants, on the other hand, fibrillar structures which were similar to the collagen were observed with electron microscope. This problem should be more thoroughly investigated in order to understand the calcification process of the animal on a ultrastructure level.
地学団体研究会の論文
1974-03-20