地学前缘 ›› 2020, Vol. 27 ›› Issue (6): 47-66.DOI: 10.13745/j.esf.sf.2020.6.21

• 早期生命演化 • 上一篇    下一篇

寒武纪叶足动物:困惑与思考

欧强1,2()   

  1. 1.中国地质大学(北京) 生物地质与环境地质国家重点实验室 早期生命演化实验室, 北京 100083
    2.西北大学 地质学系 大陆动力学国家重点实验室与早期生命与环境陕西省重点实验室, 陕西 西安 710069
  • 收稿日期:2020-06-01 修回日期:2020-07-01 出版日期:2020-11-02 发布日期:2020-11-02
  • 作者简介:欧 强(1976—),男,教授,博士生导师,主要从事动物门类起源以及寒武纪大爆发研究。E-mail: ouqiang@cugb.edu.cn
  • 基金资助:
    国家自然科学基金项目(41972009);国家自然科学基金项目(41572017);高等学校学科创新引智计划项目(B20011)

Cambrian lobopodians: confusion and consideration

OU Qiang1,2()   

  1. 1. Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing 100083, China
    2. State Key Laboratory of Continental Dynamics and Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi’an 710069, China
  • Received:2020-06-01 Revised:2020-07-01 Online:2020-11-02 Published:2020-11-02

摘要:

叶足动物在显生宙最早期的海洋中曾一度繁盛,但如今茫茫大海中它们已杳无踪影。不过,学术界主流认为它们并没有绝灭——早期叶足动物的一个分支成功演化出原始的节肢动物,成就了当今地球上最庞大的动物家族(六足类、甲壳类、多足类、螯肢类等);叶足动物另一个分支则离开海洋,保持基本躯体构型,变身为陆生叶足动物,然而历经沧桑后,仅余一两脉(有爪动物及缓步动物)残喘幸存至今。这个史诗般的精彩演化故事,深深吸引了众多学者竞先求索。近30年来,以我国云南澄江生物群为代表的一系列寒武纪特异埋藏化石库中发现了大量叶足动物化石。经研究,学术界迄今似已破解了早期叶足动物重重疑团,足以额手称庆。然而治学须严谨,考证不偏狭。作者认为,围绕早期叶足动物的迷雾尚未消散,许多问题还有待解答,部分观点仍需确证。本文对早期叶足类研究的部分主流观点提出一些不同看法,并对尚未破解的疑难问题提出尝试性的见解和猜想。

关键词: 叶足动物, 泛节肢动物, 蜕皮动物, 寒武纪, 澄江生物群

Abstract:

Marine lobopodians that boomed worldwide during the early Cambrian have been broadly considered as closely affiliated with living panarthropods, including onychophorans (velvet worms), tardigrades (water bears), and arthropods (insects, crustaceans, myriapods, chelicerates, and allies). Despite the great ecological gap, extant terrestrial onychophorans and tardigrades are widely considered as the surviving descendants of Cambrian marine lobopodians. Resemblances between early lobopodians and living onychophorans are not just caterpillar-like gross morphology but distinctive features, such as foremost the unjointed lobopodous limbs. Another lineage of early lobopodians is believed to have given birth to the earliest stem arthropods, forming the largest animal phylum on our planet today. This epic evolutionary story has attracted many scientists to speculate on their evolutionary scenarios and phylogenetic significance. However, conundrums around these enigmatic animals remain unsolved. Here, I tentatively propose some arguments against mainstream views and offer some hypothetical approaches to researches on Cambrian lobopodians.

Key words: lobopodians, Panarthropoda, Ecdysozoa, Cambrian, Chengjiang biota

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