近日，美国哈佛大学Ortega-Hernndez, Javier团队报道了携带螯肢的节肢动物揭示了螯肢动物的寒武纪起源。相关论文于2026年4月1日发表在《自然》杂志上。

螯肢类是一个物种极为丰富的节肢动物类群（超过12万种），其中包括蝎子、蜘蛛和螨等具有深远生态与经济意义的常见类群。现存螯肢类共享一个独特的解剖学特征——螯肢，即用于摄食的第一对附肢，末端为简单的钳状螯爪。这些主要营捕食生活的动物的化石记录跨度近5亿年，表明其起源很可能发生在寒武纪大爆发期间，但迄今缺乏相关证据。阿蒂奥普类、大附肢类、哈贝尔类及莫利索尼类等曾被视作寒武纪的螯肢类干群或冠群成员，但它们均缺乏明确的螯肢，因此具螯肢节肢动物的出现过程尚不清晰。

研究组描述了来自美国犹他州中寒武统的一种大型软躯体节肢动物——库斯托巨螯虫。该新属种拥有巨大的三节螯肢，五对具伪双分支结构的前体附肢（其外肢叶不呈叶片状），以及带板状鳃片的后体附肢。贝叶斯法和简约法系统发育分析均将库斯托巨螯虫定位为螯肢类的干群成员，它填补了寒武纪哈贝尔类与后寒武纪具螯肢的合螯鲎之间的演化空白。这一发现提供了寒武纪存在大型捕食性螯肢类动物的确凿证据，揭示了其身体构型的起源，并确认哈贝尔类、莫利索尼类以及很可能的大附肢类均属于螯肢类总群的成员。

附：英文原文

Title: A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates

Author: Lerosey-Aubril, Rudy, Ortega-Hernndez, Javier

Issue&Volume: 2026-04-01

Abstract: Chelicerata is a megadiverse (over 120,000 species) arthropod clade that includes familiar taxa of profound ecological and economic importance, such as scorpions, spiders and mites1. Extant chelicerates share a unique anatomical character, the chelicerae—feeding first appendages terminated by a simple pincer-like chela2. The fossil record of these primarily predatory animals spans almost 500million years3, suggesting a likely yet undocumented origin during the Cambrian Explosion. Artiopods4,5,6, megacheirans4,7,8,9, habeliids10,11,12,13 and mollisoniids14,15 have been considered Cambrian stem- or crown-group chelicerates, but they all lack unequivocal chelicerae, leaving the emergence of chelicerae-bearing arthropods unclear. Here we describe Megachelicerax cousteaui gen. et sp. nov., a large soft-bodied arthropod from the middle Cambrian of Utah featuring massive three-segmented chelicerae, along with five pairs of pseudobiramous prosomal limbs with non-foliaceous exopodal rami, and plate-like lamellae-bearing opisthosomal appendages. Bayesian and parsimony phylogenetic analyses resolve Megachelicerax as a stem-group chelicerate bridging Cambrian habeliids and post-Cambrian chelicerae-bearing synziphosurines. This finding provides unequivocal evidence of large predatory chelicerates in the Cambrian, illuminates their body plan’s origin, and confirms habeliids, mollisoniids and probably megacheirans as members of total-group Chelicerata.

DOI: 10.1038/s41586-026-10284-2

Source: https://www.nature.com/articles/s41586-026-10284-2