英国杜伦大学Martin R. Smith等研究人员发现寒武纪真节肢动物幼虫的器官系统。这一研究成果于2024年7月31日在线发表在国际学术期刊《自然》上。

研究人员描述了一种三维保存的具有叶足、中肠腺和复杂头部的真节肢动物幼虫的内部和外部解剖结构。神经系统的结构揭示了真节肢动物大脑及其相关附肢和感觉器官的早期配置，澄清了泛节肢动物之间的同源关系。Youti yuanshi gen. et sp. nov.的深层演化位置揭示了节肢动物演化过程中特征获取的顺序，展示了复杂的血淋巴循环系统的深层起源，并阐明了推动这一成功群体崛起和多样化的内部解剖变化。

据了解，寒武纪辐射的真节肢动物可以归因于其适应性强的身体结构。复杂的大脑和专门的进食附肢，这些都是重复的器官系统和关节附肢的延伸，支撑了真节肢动物在广泛的生态环境中的主导地位。真节肢动物身体结构的起源可以追溯到具有水力静力性叶足附肢的蠕虫状类群（“叶足蠕虫”），这一点是基于伯吉斯页岩类型化石的数据。然而，这种保存方式的压缩会掩盖内部解剖结构。磷酸盐化的微化石提供了早期冠群真节肢动物的三维视角，但很少有叶足动物。

附：英文原文

Title: Organ systems of a Cambrian euarthropod larva

Author: Smith, Martin R., Long, Emma J., Dhungana, Alavya, Dobson, Katherine J., Yang, Jie, Zhang, Xiguang

Issue&Volume: 2024-07-31

Abstract: The Cambrian radiation of euarthropods can be attributed to an adaptable body plan. Sophisticated brains and specialized feeding appendages, which are elaborations of serially repeated organ systems and jointed appendages, underpin the dominance of Euarthropoda in a broad suite of ecological settings. The origin of the euarthropod body plan from a grade of vermiform taxa with hydrostatic lobopodous appendages (‘lobopodian worms’)1,2 is founded on data from Burgess Shale-type fossils. However, the compaction associated with such preservation obscures internal anatomy3,4,5,6. Phosphatized microfossils provide a complementary three-dimensional perspective on early crown group euarthropods7, but few lobopodians8,9. Here we describe the internal and external anatomy of a three-dimensionally preserved euarthropod larva with lobopods, midgut glands and a sophisticated head. The architecture of the nervous system informs the early configuration of the euarthropod brain and its associated appendages and sensory organs, clarifying homologies across Panarthropoda. The deep evolutionary position of Youti yuanshi gen. et sp. nov. informs the sequence of character acquisition during arthropod evolution, demonstrating a deep origin of sophisticated haemolymph circulatory systems, and illuminating the internal anatomical changes that propelled the rise and diversification of this enduringly successful group.

DOI: 10.1038/s41586-024-07756-8

Source: https://www.nature.com/articles/s41586-024-07756-8