卵壳的超微结构特征

本文运用扫描电镜研究了美洲鸵鸟,鹂鹋,非洲鸵鸟,普通家鸡,环颈雉,绿头鸭,王企鹅等七种现生鸟蛋壳和更新世安氏鸵鸟蛋壳以及六种白垩纪恐龙蛋壳（长形长形蛋Ｅｌｏｎｇａｔｏｏｌｉｔｈｕｓｅｌｏｎｇａｔｕｓ,安氏长形蛋Ｅｌｏｎｇａｔｏｏｌｉｔｈｕｓａｎｄｒｅｗｓｉ,瑶屯巨形蛋Ｍａｃｒｏｏｌｉｔｈｕｓｙａｏｔｕｎｅｎｓｉｓ粗皮巨形蛋Ｍａｃｒｏｏｌｉｔｈｕｓｒｕｇｕｓｔｕｓ,将军顶圆形蛋Ｓｐｈｅｒｏｏｌｉｔｈ

A STUDY OF EGGSHELLS WITH SCANNING ELECTRON MICROSCOPE

The study of eggshell ultrastructure is still a relatively young discipline, encompassing only a few of the numerous kinds of eggshells. In this paper, structures of calcareous eggshells of living and or fossil birds and dinosaurs have been studied with scanning electron microscope. The terminology of eggshell structure is very confusing and in need of clarification. Therefore, a new eggshell model and the relevant terminology based on well-studied avian eggshell are proposed. The new model differs from that of Mikhailov's (1992) in using "mammilla" instead of "eisospherite" and "mammillary core", "cuneus" instead of "wedge", employing "blocky crystal unit" instead of"squamatic unit", "blocky ultrastructure "instead of "squamatic ultrastructure", adding reticulate layer between column layer and surface crystal layer, replacing "extern zone" with "surface crystal layer" and substituting "cover" and "cuticle" for "tegmentum". All terms except "blocky crystal unit" and "blocky ultrastructure" were introduced by other authors. Some evidences indicated that the labular ultrastructure, characteristic of cuneus, is entirely under crystallographic control, Many blocky crystal units act together as a monocrystal. The structure of the surface crystal layer of various groups is different. The new model is applicable not only to the study of avian eggshells but also to that of dinosaur eggshells. Eggshell structure of Elongatoolithidae is similar to thatof Ratitae. Column layer of Ovaloolithus chinkangkouensis can be divided into two distinct layers: striate texture in the inner laner umbrella-like striation in the outer.