中文摘要：

在关于的进化发展生物学有世纪长的争论祖先后生动物一幼虫或一个成年人。二竞争假设被建议了：终端增加理论，假定幼虫的原始，和置闰理论。一致还没被到达了，但是终端增加理论看起来是广泛地接受的更多。与在生活 metazoans 之中的幼虫的多数相对照，然而，象 Markuelia 和 Olivooides 那样的所有当前已知的石块无脊椎动物胚胎是直接开发者。这里，我们描述 Eolarva kuanchuanpuensis 情报。et sp。nov，最旧知道幼虫，从早寒武纪(~ 535Ma ) 华南。Eolarva kuanchuanpuensis 缺乏一张嘴或喂仪器的任何另外的类型，它是非喂的或 lecithotrophic。它拥有一个不同身体计划和力量代表一个 cnidarian 等级动物。这是显示间接开发是后生动物的开发的 plesiomorphy 的第一条石块证据。

英文摘要：

There has been a century-long debate in evo- lutionary developmental biology about whether the ancestral metazoan was a larva or an adult. Two competing hypotheses have been proposed： the ＂terminal addition＂ theory, which assumes the primitiveness of larvae, and the ＂intercalation＂ theory, which assumes the primitiveness of adults. A consensus has not yet been reached, but the ＂terminal addition＂ theory appears to be more widely accepted. However, in contrast to the majority of larvae among living metazoans, all currently known fossil inver- tebrate embryos such as Markuelia and Olivooides are direct developers. Here, we describe Eolarva kuanchuan- puensis gen. et sp. nov., the oldest known larva, from the early Cambrian （-535 Ma） of South China. Eolarva kuanchuanpuensis lacks a mouth or any other type of feeding apparatus, which is non-feeding or lecithotrophic. It possesses a distinct body plan and might represent a cnidarian-grade animal. This is the first fossil evidence indicating that indirect development is the plesiomorphy of metazoan development.