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阿纳巴管(Anabarites)是寒武纪早期一类形态独特的管栖生物,其横切面的轮廓多样,但所有形态都是“3”的倍数。陕南梅树村期西乡生物群产出大量磷质Anabarites,根据管体上纵槽出现的数目和级别,确认Anabarites可分辨出三种对称类型:A型为仅具有三条一级纵槽的三辐射对称类型、B型具有三条一级纵槽和一条二级纵槽类型、C型具有三条一级纵槽和两条二级纵槽。其中B型、C型是从三辐射到六辐射对称之间的过渡类型,为新发现的对称形式。本文以上述三种类型Anabarites为研究材料,对Anabarites对称性演化途径进行了探索性研究,对寒武纪大爆发之初动物的对称性起源演化研究提供了重要证据。
The Anabarites, a distinctive species of tubular amphibian of the early Cambrian, have a variety of cross-sectional profiles, but all patterns are multiples of “3”. According to the number and grade of vertical grooves in pipe body, there are three kinds of symmetry types identified by Anabarites: type A is Anabarites with only three first-grade longitudinal grooves Three Radiation Symmetry Types, Type B has three first-grade longitudinal grooves and one second-grade longitudinal groove type, and C-Type has three first-grade longitudinal grooves and two second-grade longitudinal grooves. Among them, type B and type C are transition types from three radiations to six radiations symmetry, which is a newly found symmetrical form. In this paper, three types of Anabarites were selected as the research materials to explore the evolutionary pathways of Anabarites symmetry, which provided important evidences for the study of the origin and evolution of symmetry in early Cambrian explosion.