Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China.
MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China.
PeerJ. 2023 Nov 7;11:e16385. doi: 10.7717/peerj.16385. eCollection 2023.
The Cambrian Radiation represents one of the largest diversification events in Earth history. While the resulting taxonomic diversity is exceptional, relatively few of these novel species can be traced outside the boundaries of a single palaeocontinent. Many of those species with cosmopolitan distributions were likely active swimmers, presenting opportunity and means to conquer new areas, but this would not have been the case for sessile organisms. is a lower to middle Cambrian (Series 2-Miaolingian, Stage 3-Wuliuan) genus of sessile, stalked, filter-feeding deuterostomes with two species, and , known respectively from Laurentia and Gondwana. Here, we expand the distribution of to Gondwana with newly discovered specimens from the Balang Formation of Hunan, China. This discovery raises questions on the origin of the genus and how sessile organisms were able to disperse over such a broad distance in the lower Cambrian. As has been recovered at the base of the Ambulacrarian tree in recent phylogenies, a planktonic larval stage is suggested, which implies, that the last common ancestor of the Ambulacraria might have already had planktonic larvae or that such larvae developed multiple times within the Ambulacraria.
寒武纪辐射代表了地球历史上最大的多样化事件之一。虽然由此产生的分类多样性异常，但这些新物种中只有相对较少的物种可以追溯到单个古大陆的边界之外。许多具有世界性分布的物种可能是活跃的游泳者，有机会和手段征服新的地区，但对于固着生物来说并非如此。是一种下至中寒武纪（统 2-苗岭统，阶 3-五峰阶）的固着、具柄、滤食后口动物属，有两个种， 和 ，分别来自劳伦西亚和冈瓦纳。在这里，我们通过在中国湖南巴朗组发现的新标本，将 的分布范围扩大到了冈瓦纳。这一发现引发了关于该属起源以及固着生物如何在寒武纪早期如此广泛的距离内扩散的问题。由于 在最近的系统发育中被发现在节肢动物树的基部，因此暗示了浮游幼虫阶段的存在，这意味着节肢动物的最后共同祖先可能已经具有浮游幼虫，或者这种幼虫在节肢动物中多次发育。
