鏈狀心網蟲學名Cardiodictyon catenulum[1])是心網蟲科學名Cardiodictyidae[3]心網蟲屬學名Cardiodictyon[1])的唯一一個物種[1][4],也是模式種。此物種在中國南方發現的。[3][1]生存在中寒武紀。[1]此物種的化石標本非常普遍,總共發現多達兩百多個心網蟲的化石標本,而且大多發現的標本是扁的,而且是彎曲的,[4]再加上化石保存都很好。[5]心網蟲的頭部具有兩對的前附肢[3][6],頭裡還有可能類似大腦的器官[7][8][9][10][11],頭部區域是箭頭狀,前面的邊緣是圓形。其頭部由一對大骨片保護,頭部前緣有雙重結構[3],並有一對眼點[12]; 背板的形狀也被重新詮釋。[3]嘴巴和肛門位於身體前後的末端。[8]身體很細長還有一條條的環紋[13],23對邊邊很尖的六角形的骨片,還有23對腳,而腳上兩個爪子。[3][1]怪誕蟲屬Hallucigenia)其中的一種強壯怪誕蟲 (Hallucigenia fortis),因為既有身長的身軀[14][15][16],與心網蟲一樣都是在中國發現的。[1]囉哩山蟲屬Luolishania)、微網蟲屬英语MicrodictyonMicrodictyon)、貧腿蟲屬Paucipodia[17]爪網蟲屬Onychodictyon[1]都是在中國早期發現的基群泛節肢生物[6][18]

鏈狀心網蟲
化石时期:521–514 Ma
寒武紀第三期[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
並系群 葉足動物 Lobopodia
纲: 異蟲綱 Xenusia
目: 堅有爪目 Scleronychophora
演化支 怪誕蟲類群 Hallucigeniids
科: 心網蟲科 Cardiodictyidae
Hou & Bergstrom, 1995[3]
属: 心網蟲屬 Cardiodictyon
Hou, Ramsköld, and Bergström, 1991[1]
种:
鏈狀心網蟲 C. catenulum
二名法
Cardiodictyon catenulum
Hou, Ramsköld, and Bergström, 1991

命名 编辑

心網蟲屬是在中國雲南省澂江市澄江化石地發現的。[3][4][19]是源自希臘語kardia是指心, 和dictyon是網子的意思。catenula是源自拉丁語, 意指小鍊條或是鐵鍊,是指心網蟲身上的一排一排的骨板。[3]

描述 编辑

 
鏈狀心網蟲的整體附原圖。
 
異蟲英语XenusionXenusion)在海底爬行的復原圖,旁邊還有暗紅色的水母。與心網蟲都是以爬行移動。

頭部看起來像是橢圓形或是半圓形[4][20],頭部有原本被發現有三對細長的前附肢,其中兩對已經確定存在,第三對當時還不能確定[1],而之後的研究發現只有兩對前附肢。[6][21][20][22],位在頭部骨片的更前面。[20]頭部的一端被一對大骨片覆蓋[3][13][20][22][23],頭部有分節[6],沒有大骨片的頭部看起來就像末端[1],頭部和尾部的末端逐漸變得細。[3]在頭部上還有細小的眼點。[3][4][12][20][24]身體細長[3][4],大約身長3公分、1公分寬[4],身體沒有分節[6],還有25對附肢(頭部的兩對附肢加上身體的二十三對用來行走的腳)[25][26][27],共有23塊的網狀六角形骨片[3][13][25][26][28][註 1],每個骨片與骨片的間隔總是有規律的,最後一塊的骨片在後面就是身體的尾部,而且尾部是鈍的。[3]原本以為身上是沒有環紋[1],後來證明有一條條的環紋。[13]發現有一從頭部延伸身體的末端條縱向的暗黑色寬帶,推測可能是腸子。[3][4][13][29]整個身體的骨板形狀幾乎沒什麼變化,每隔一對骨板,也就有一對腳。[3]這一些腳很長,大約是身體寬度的三倍。[1]當初而底部的爪子保存的不完整[1],因而誤以為有四、五個爪子[1][3],而之後發現其實只有兩個爪子。[25]

 
加拿大奇蝦Anomalocaris canadensis)正在用前附肢捕捉在游泳的等刺虫属Isoxys)。心網蟲可能與奇蝦一樣用附肢捕食。

生活 编辑

對心網蟲的生活幾乎一無所知,有一些甚至是以對其他寒武紀葉足動物認知而成的。心網蟲是底棲型的物種,因為具有用來行走的腳,發現的腸子可能代表心網蟲是肉食性或是雜食性,且頭上兩對的附肢可能與放射齒目一樣,用來抓捕獵物。[4]

資料來源 编辑

  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. 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. ^ 通常發現心網蟲化石標本都是發現側面的,所以骨片看起來類似三角形;如果以背側骨片看,那看到的是類似六角形。