心網蟲屬

鏈狀心網蟲（學名：Cardiodictyon catenulum）是心網蟲科（學名：Cardiodictyidae）心網蟲屬（學名：Cardiodictyon）的唯一一個物種，也是模式種。此物種在中國南方發現的。生存在中寒武紀。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，再加上化石保存都很好。心網蟲的頭部具有兩對的前附肢，頭裡還有可能類似大腦的器官，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，並有一對眼點； 背板的形狀也被重新詮釋。嘴巴和肛門位於身體前後的末端。身體很細長還有一條條的環紋，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。與怪誕蟲屬（Hallucigenia）其中的一種強壯怪誕蟲 （Hallucigenia fortis），因為既有身長的身軀，與心網蟲一樣都是在中國發現的。與囉哩山蟲屬（Luolishania）、微網蟲屬（英语：Microdictyon）（Microdictyon）、貧腿蟲屬（Paucipodia）、爪網蟲屬 （Onychodictyon）都是在中國早期發現的基群泛節肢生物。 心網蟲屬是在中國雲南省澂江市的澄江化石地發現的。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。 頭部看起來像是橢圓形或是半圓形，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，而之後的研究發現只有兩對前附肢。，位在頭部骨片的更前面。頭部的一端被一對大骨片覆蓋，頭部有分節，沒有大骨片的頭部看起來就像末端，頭部和尾部的末端逐漸變得細。在頭部上還有細小的眼點。身體細長，大約身長3公分、1公分寬，身體沒有分節，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），共有23塊的網狀六角形骨片，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。原本以為身上是沒有環紋，後來證明有一條條的環紋。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。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。這一些腳很長，大約是身體寬度的三倍。當初而底部的爪子保存的不完整，因而誤以為有四、五個爪子，而之後發現其實只有兩個爪子。 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。 XIANGUANG, HOU; RAMSKÖLD, LARS; BERGSTRÖM, JAN. 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The lobopodian Paucipodia inermis from the Lower Cambrian Chengjiang fauna, Yunnan, China. Lethaia. 2004-09, 37 (3). ISSN 0024-1164. doi:10.1080/00241160410006555.  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。