链状心网虫学名Cardiodictyon catenulum[1])是心网虫科学名Cardiodictyidae[3]心网虫属学名Cardiodictyon[1])的唯一一个物种[1][4],也是模式种。此物种在中国南方发现的。[3][1]生存在中寒武纪。[1]此物种的化石标本非常普遍,总共发现多达两百多个心网虫的化石标本,而且大多发现的标本是扁的,而且是弯曲的,[4]再加上化石保存都很好。[5]心网虫的头部具有两对的前附肢[3][6],头里还有可能类似大脑的器官[7][8][9][10][11],头部区域是箭头状,前面的边缘是圆形。其头部由一对大骨片保护,头部前缘有双重结构[3],并有一对眼点[12]; 背板的形状也被重新诠释。[3]嘴巴和肛门位于身体前后的末端。[8]身体很细长还有一条条的环纹[13],23对边边很尖的六角形的骨片,还有23对脚,而脚上两个爪子。[3][1]怪诞虫属Hallucigenia)其中的一种强壮怪诞虫 (Hallucigenia fortis),因为既有身长的身躯[14][15][16],与心网虫一样都是在中国发现的。[1]啰哩山虫属Luolishania)、微网虫属英语MicrodictyonMicrodictyon)、贫腿虫属Paucipodia[17]爪网虫属Onychodictyon[1]都是在中国早期发现的基群泛节肢生物[6][18]

链状心网虫
化石时期:521–514 Ma
寒武纪第三期[1][2]
科学分类 编辑
界: 动物界 Animalia
总门: 蜕皮动物总门 Ecdysozoa
演化支 泛节肢动物 Panarthropoda
并系群 叶足动物 Lobopodia
纲: 异虫纲 Xenusia
目: 坚有爪目 Scleronychophora
演化支 怪诞虫类群 Hallucigeniids
科: 心网虫科 Cardiodictyidae
Hou & Bergstrom, 1995[3]
属: 心网虫属 Cardiodictyon
Hou, Ramsköld, and Bergström, 1991[1]
种:
链状心网虫 C. catenulum
二名法
Cardiodictyon catenulum
Hou, Ramsköld, and Bergström, 1991

命名

编辑

心网虫属是在中国云南省澂江市澄江化石地发现的。[3][4][19]是源自希腊语kardia是指心, 和dictyon是网子的意思。catenula是源自拉丁语, 意指小链条或是铁链,是指心网虫身上的一排一排的骨板。[3]

描述

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链状心网虫的整体附原图。
 
异虫英语XenusionXenusion)在海底爬行的复原图,旁边还有暗红色的水母。与心网虫都是以爬行移动。

头部看起来像是椭圆形或是半圆形[4][20],头部有原本被发现有三对细长的前附肢,其中两对已经确定存在,第三对当时还不能确定[1],而之后的研究发现只有两对前附肢。[6][21][20][22],位在头部骨片的更前面。[20]头部的一端被一对大骨片覆盖[3][13][20][22][23],头部有分节[6],没有大骨片的头部看起来就像末端[1],头部和尾部的末端逐渐变得细。[3]在头部上还有细小的眼点。[3][4][12][20][24]身体细长[3][4],大约身长3公分、1公分宽[4],身体没有分节[6],还有25对附肢(头部的两对附肢加上身体的二十三对用来行走的脚)[25][26][27],共有23块的网状六角形骨片[3][13][25][26][28][注 1],每个骨片与骨片的间隔总是有规律的,最后一块的骨片在后面就是身体的尾部,而且尾部是钝的。[3]原本以为身上是没有环纹[1],后来证明有一条条的环纹。[13]发现有一从头部延伸身体的末端条纵向的暗黑色宽带,推测可能是肠子。[3][4][13][29]整个身体的骨板形状几乎没什么变化,每隔一对骨板,也就有一对脚。[3]这一些脚很长,大约是身体宽度的三倍。[1]当初而底部的爪子保存的不完整[1],因而误以为有四、五个爪子[1][3],而之后发现其实只有两个爪子。[25]

 
加拿大奇虾Anomalocaris canadensis)正在用前附肢捕捉在游泳的等刺虫属Isoxys)。心网虫可能与奇虾一样用附肢捕食。

生活

编辑

对心网虫的生活几乎一无所知,有一些甚至是以对其他寒武纪叶足动物认知而成的。心网虫是底栖型的物种,因为具有用来行走的脚,发现的肠子可能代表心网虫是肉食性或是杂食性,且头上两对的附肢可能与放射齿目一样,用来抓捕猎物。[4]

资料来源

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  1. ^ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 XIANGUANG, HOU; RAMSKÖLD, LARS; BERGSTRÖM, JAN. Composition and preservation of the Chengjiang fauna –a Lower Cambrian soft‐bodied biota. Zoologica Scripta. 1991-10, 20 (4). ISSN 0300-3256. doi:10.1111/j.1463-6409.1991.tb00303.x. 
  2. ^ Ou, Qiang; Mayer, Georg. A Cambrian unarmoured lobopodian, †Lenisambulatrix humboldti gen. et sp. nov., compared with new material of †Diania cactiformis. Scientific Reports. 2018-09-20, 8 (1). ISSN 2045-2322. doi:10.1038/s41598-018-31499-y. 
  3. ^ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 HOU, XIANGUANG; BERGSTRÖM, JAN. Cambrian lobopodians-ancestors of extant onychophorans? (PDF). Zoological Journal of the Linnean Society. 1995-05, 114 (1). ISSN 0024-4082. doi:10.1111/j.1096-3642.1995.tb00110.x. 
  4. ^ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Hou, X., Aldridge, R. J., Bergström, J., Siveter, D. J., Siveter, D. J., & Xiang-Hong, F. (2004). The Cambrian fossils of Chengjiang, China: the flowering of early animal life (Vol. 233, pp. 1-233). Oxford: Blackwell.
  5. ^ Han, Jian; Shu, Degan; Zhang, Zhifei; Liu, Jianni; Zhang, Xingliang; Yao, Yang. Preliminary notes on soft-bodied fossil concentrations from the Early Cambrian Chengjiang deposits. Chinese Science Bulletin. 2006-10, 51 (20). ISSN 1001-6538. doi:10.1007/s11434-005-2151-0. 
  6. ^ 6.0 6.1 6.2 6.3 6.4 Chen, Jun-Yuan. The sudden appearance of diverse animal body plansduring the Cambrian explosion. The International Journal of Developmental Biology. 2009, 53 (5-6). ISSN 0214-6282. doi:10.1387/ijdb.072513cj. 
  7. ^ Smith, Frank W.; Game, Mandy; Mapalo, Marc A.; Chavarria, Raul A.; Harrison, Taylor R.; Janssen, Ralf. Developmental and genomic insight into the origin of the tardigrade body plan. Evolution & Development. 2023-09-18. ISSN 1520-541X. doi:10.1111/ede.12457. 
  8. ^ 8.0 8.1 Strausfeld, Nicholas J.; Hou, Xianguang; Sayre, Marcel E.; Hirth, Frank. The lower Cambrian lobopodian Cardiodictyon resolves the origin of euarthropod brains. Science. 2022-11-25, 378 (6622). ISSN 0036-8075. doi:10.1126/science.abn6264. 
  9. ^ Budd, Graham E.; Mayer, Georg; Janssen, Ralf; Eriksson, B. Joakim. Comment on “The lower Cambrian lobopodian Cardiodictyonresolves the origin of euarthropod brains”. Science. 2023-06-30, 380 (6652). ISSN 0036-8075. doi:10.1126/science.adg1412. 
  10. ^ Strausfeld, Nicholas J.; Hou, Xianguang; Sayre, Marcel E.; Hirth, Frank. Response to Comment on “The lower Cambrian lobopodian Cardiodictyon resolves the origin of euarthropod brains”. Science. 2023-06-30, 380 (6652). ISSN 0036-8075. doi:10.1126/science.adg6051. 
  11. ^ Briggs, Derek E. G.; Parry, Luke A. Putting heads together. Science. 2022-11-25, 378 (6622). ISSN 0036-8075. doi:10.1126/science.add7372. 
  12. ^ 12.0 12.1 Ma, Xiaoya; Hou, Xianguang; Aldridge, Richard J.; Siveter, David J.; Siveter, Derek J.; Gabbott, Sarah E.; Purnell, Mark A.; Parker, Andrew R.; Edgecombe, Gregory D. Morphology of Cambrian lobopodian eyes from the Chengjiang Lagerstätte and their evolutionary significance. Arthropod Structure & Development. 2012-09, 41 (5). ISSN 1467-8039. doi:10.1016/j.asd.2012.03.002. 
  13. ^ 13.0 13.1 13.2 13.3 13.4 Waloszek, Dieter; Maas, Andreas; Chen, Junyuan; Stein, Martin. Evolution of cephalic feeding structures and the phylogeny of Arthropoda. Palaeogeography, Palaeoclimatology, Palaeoecology. 2007-10, 254 (1-2). ISSN 0031-0182. doi:10.1016/j.palaeo.2007.03.027. 
  14. ^ Smith, Martin R.; Ortega-Hernández, Javier. Hallucigenia’s onychophoran-like claws and the case for Tactopoda. Nature. 2014-08-17, 514 (7522). ISSN 0028-0836. doi:10.1038/nature13576. 
  15. ^ Smith, Martin R.; Caron, Jean-Bernard. Hallucigenia’s head and the pharyngeal armature of early ecdysozoans. Nature. 2015-06-24, 523 (7558). ISSN 0028-0836. doi:10.1038/nature14573. 
  16. ^ Yang, Jie; Ortega-Hernández, Javier; Gerber, Sylvain; Butterfield, Nicholas J.; Hou, Jin-bo; Lan, Tian; Zhang, Xi-guang. A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora. Proceedings of the National Academy of Sciences. 2015-06-29, 112 (28). ISSN 0027-8424. doi:10.1073/pnas.1505596112. 
  17. ^ Jun-yuan, Chen; Gui-qing, Zhou; Ramsköld, Lars. A new Early Cambrian onychophoran-like animal, Paucipodia gen. nov., from the Chengjiang fauna, China. Transactions of the Royal Society of Edinburgh: Earth Sciences. 1994, 85 (4). ISSN 0263-5933. doi:10.1017/s0263593300002042. 
  18. ^ Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C. Sophisticated digestive systems in early arthropods. Nature Communications. 2014-05-02, 5 (1). ISSN 2041-1723. doi:10.1038/ncomms4641. 
  19. ^ Maas, Andreas; Mayer, Georg; Kristensen, Reinhardt M.; Waloszek, Dieter. A Cambrian micro-lobopodian and the evolution of arthropod locomotion and reproduction. Chinese Science Bulletin. 2007-12, 52 (24). ISSN 1001-6538. doi:10.1007/s11434-007-0515-3. 
  20. ^ 20.0 20.1 20.2 20.3 20.4 Ma, Xiaoya; Hou, Xianguang; Bergström, Jan. Morphology of Luolishania longicruris (Lower Cambrian, Chengjiang Lagerstätte, SW China) and the phylogenetic relationships within lobopodians. Arthropod Structure & Development. 2009-07, 38 (4). ISSN 1467-8039. doi:10.1016/j.asd.2009.03.001. 
  21. ^ Dzik, J. (2011). The xenusian-to-anomalocaridid transition within the lobopodians.页面存档备份,存于互联网档案馆Boll Della Soc Paleontol Ital, 50, 65-74.
  22. ^ 22.0 22.1 Liu, JianNi; Shu, DeGan; Han, Jian; Zhang, ZhiFei. Comparative study of Cambrian lobopods Miraluolishania and Luolishania. Chinese Science Bulletin. 2008-01, 53 (1). ISSN 1001-6538. doi:10.1007/s11434-007-0428-1. 
  23. ^ Bergström, J.a.n.; Hou, Xian-Guang. Cambrian Onychophora or Xenusians. Zoologischer Anzeiger - A Journal of Comparative Zoology. 2001-01, 240 (3-4). ISSN 0044-5231. doi:10.1078/0044-5231-00031. 
  24. ^ Liu, Jianni; Dunlop, Jason A. Cambrian lobopodians: A review of recent progress in our understanding of their morphology and evolution. Palaeogeography, Palaeoclimatology, Palaeoecology. 2014-03, 398. ISSN 0031-0182. doi:10.1016/j.palaeo.2013.06.008. 
  25. ^ 25.0 25.1 25.2 Liu, Jianni; Shu, Degan; Han, Jian; Zhang, Zhifei; Zhang, Xingliang. Origin, diversification, and relationships of Cambrian lobopods. Gondwana Research. 2008-08, 14 (1-2). ISSN 1342-937X. doi:10.1016/j.gr.2007.10.001. 
  26. ^ 26.0 26.1 Bergström, J.a.n.; Hou, Xian-Guang. Cambrian Onychophora or Xenusians. Zoologischer Anzeiger - A Journal of Comparative Zoology. 2001-01, 240 (3-4). ISSN 0044-5231. doi:10.1078/0044-5231-00031. 
  27. ^ Siveter, Derek J.; Briggs, Derek E. G.; Siveter, David J.; Sutton, Mark D.; Legg, David. A three-dimensionally preserved lobopodian from the Herefordshire (Silurian) Lagerstätte, UK. Royal Society Open Science. 2018-08, 5 (8). ISSN 2054-5703. doi:10.1098/rsos.172101. 
  28. ^ Smith, Martin Ross; Dhungana, Alavya. Discussion on Tabelliscolex (Cricocosmiidae: Palaeoscolecidomorpha) from the early Cambrian Chengjiang Biota and the evolution of seriation in Ecdysozoa’ by Shiet al.2021 (JGS, jgs2021-060). Journal of the Geological Society. 2022-01-28, 179 (3). ISSN 0016-7649. doi:10.1144/jgs2021-111. 
  29. ^ Hou, Xian‐Guang; Ma, Xiao‐Ya; Zhao, Jie; Bergström, Jan. The lobopodian Paucipodia inermis from the Lower Cambrian Chengjiang fauna, Yunnan, China. Lethaia. 2004-09, 37 (3). ISSN 0024-1164. doi:10.1080/00241160410006555. 
  1. ^ 通常发现心网虫化石标本都是发现侧面的,所以骨片看起来类似三角形;如果以背侧骨片看,那看到的是类似六角形。