Vannier Jean
Université de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, CNRS UMR 5276, Laboratoire de géologie de Lyon: Terre, Planètes, Environnement, Bâtiment GEODE, Villeurbanne 69622, France.
Proc Biol Sci. 2024 Dec;291(2036):20241256. doi: 10.1098/rspb.2024.1256. Epub 2024 Dec 4.
With its bag-like appearance, spiny ornament and single opening, is one of the most enigmatic animals of the early Cambrian Kuanchuanpu Formation ( 535 Ma) and has been at the heart of debates concerning the origin of two major animal lineages: the deuterostomes and the ecdysozoans. Although Ecdysozoa is now the most plausible option, key aspects of its palaeobiology have remained elusive. I suggest here that was the possible larval stage of one of the numerous scalidophoran worms that co-existed with it in the Kuanchuanpu biota, especially those with bilateral pairs of broad-based sclerites such as . This new interpretation is mainly based on the development of extant priapulid worms (Scalidophora). It would imply that is a non-feeding larva and that its enigmatic single aperture with a pleated structure is not a mouth but more likely the opening through which the juvenile exited. Thus, the strange anatomy of could be explained in a simple way without involving complex evolutionary processes (e.g. simplification, miniaturization, loss of anus, etc.). Instead of being a relatively basal member of the total group Ecdysozoa, would find a more likely position among the total group Scalidophora.
因其袋状外形、多刺装饰和单一开口,是寒武纪早期宽川铺组(5.35亿年前)最神秘的动物之一,一直是有关两个主要动物谱系起源争论的核心:后口动物和蜕皮动物。尽管蜕皮动物现在是最合理的选择,但其古生物学的关键方面仍然难以捉摸。我在此提出,它可能是宽川铺生物群中与它共存的众多鳃曳动物蠕虫之一的幼虫阶段,特别是那些具有双侧成对宽基骨片的蠕虫,如[具体物种名未给出]。这一新解释主要基于现存鳃曳虫类蠕虫(鳃曳动物)的发育。这意味着它是一种不进食的幼虫,其神秘的带有褶皱结构的单一开口不是口,而更可能是幼体离开的开口。因此,它奇怪的解剖结构可以用一种简单的方式来解释,而无需涉及复杂的进化过程(如简化、小型化、肛门缺失等)。它不是蜕皮动物总群中相对基础的成员,而是更可能在鳃曳动物总群中找到一个位置。