简述了水母的早期化石记录，并根据华南寒武系发现的立方水母干群化石，讨论了祖先型水母的辐射对称、躯体构型、生活史、生活习性，以及外骨骼的形成特征，推测水母类在寒武纪大爆发初期先于两侧对称动物基本完成其高级分类单元的宏演化。寒武纪的水母在生活习性上可以分为底栖固着型和游泳型两种。We introduced the fossil records of medusa in brief and discussed the radial symmetry, body plan, life history, and exoskeleton of ancestral medusae. It is hypothesized that major clades of superclass medusa should have derived prior to that of ballerinas at the dawn of Cambrian explosion. The Cambrian medusae should be classified as sessile benthic and pelagic forms
