The arrangement of possible muscle fibres in the Ediacaran taxon Haootia quadriformis

Haootia quadriformis from Newfoundland, Canada, is one of the most unusual impressions of a soft-bodied macro-organism yet described from the late Ediacaran Period. Interpreted as a metazoan of cnidarian grade, the body impression of H. quadriformis possesses features interpreted as fibrous structures that represent possible evidence for muscular tissue. Evidence both in support of and against a relationship between H. quadriformis and the Staurozoa, one of the cnidarian groups to which Haootia was compared in Liu et al., is outlined by Miranda et al.. Our intention in our original paper was to illustrate the staurozoan body plan for comparative purposes, rather than suggest homology or direct ancestry. Nevertheless, fresh insights from workers with expertise in the biology of extant cnidarians are welcomed.产自加拿大纽芬兰的四形哈奥特虫（Haootia quadriformis）是迄今埃迪卡拉纪晚期（late Ediacaran Period）地层中已被正式描述的最特殊的软躯体宏体生物印痕化石类群之一。该生物被解读为刺胞动物（cnidarian）级别的后生动物（metazoan），其躯体印痕带有被解释为纤维状结构的特征，这些结构或可作为肌肉组织存在的佐证。米兰达等人（Miranda et al.）梳理了支持与反对四形哈奥特虫与十字水母纲（Staurozoa）存在亲缘关系的相关证据——十字水母纲是刘等人（Liu et al.）的研究中曾将四形哈奥特虫与之比对的刺胞动物类群之一。我们在原始论文中的核心意图，是为开展比较研究而展示十字水母纲的躯体构型，而非提出二者存在同源性或直接祖先关联。尽管如此，我们仍欢迎从事现生刺胞动物生物学研究的专家学者提供新的研究见解。