A new xandarellid euarthropod from the Cambrian Chengjiang biota, Yunnan Province, China
A new xandarellid euarthropod from the Cambrian Chengjiang biota, Yunnan Province, China
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DOI：
10.1017/s0016756818000730
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发表时间：
2018-12
影响因子：
2.3
通讯作者：
X. Hou;Mark Williams;Robert S. Sansom;D. Siveter;D. Siveter;S. Gabbott;T. Harvey;Pei-yun Cong;Yu Liu
中科院分区：
文献类型：
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作者：
X. Hou;Mark Williams;Robert S. Sansom;D. Siveter;D. Siveter;S. Gabbott;T. Harvey;Pei-yun Cong;Yu Liu
摘要 真节肢动物 Luohuilineella deletres sp.十一月是从中国云南省寒武纪系列 2、第 3 阶段澄江生物群的稀有材料中描述的。系统发育分析恢复了 xandarellid 对 L. deletres 的亲和力，仅代表该分支中第五个已描述的物种。 L. deletres 拥有约占全身长度五分之一的头盾，躯干有 30 个背节，最前面的背节减少，末端的 3 个背节缺乏胸膜伸长。头盾中位于前面的凹口与有柄的眼睛相关，这与 Xandarella 中存在的更靠后的、封闭的眼缝形成鲜明对比。触角后方至少保留有 11 对双臂附肢，其中头部有 3 对。 L. deletres 中线肠道的形态，其中侧面的、不分支的憩室向身体前部较宽，也是各种三叶虫的一个特征。与其他三叶形动物一样，背腹扁平的外骨骼表明 L. deletres 具有底栖或底栖生活模式，并且它很可能利用其发育良好的位于前方的眼睛来寻找食物，以清除或寻找猎物。
Abstract The euarthropod Luohuilinella deletres sp. nov. is described from rare material from the Chengjiang biota, Cambrian Series 2, Stage 3, of Yunnan Province, China. Phylogenetic analysis recovers a xandarellid affinity for L. deletres, representing only the fifth described species of this clade. L. deletres possesses a head shield that is about one-fifth of the total body length and a trunk with 30 tergites, the reduced anterior-most tergite and terminal three tergites lacking pleural elongations. Anteriorly situated notches in the head shield are associated with stalked eyes, in contrast to the more posterior, enclosed eye slits present in Xandarella. Posterior to the antennae there are at least 11 pairs of biramous appendages preserved, including three pairs in the head. The morphology of the midline gut of L. deletres, in which lateral, unbranched diverticula are wider towards the front of the body, is a characteristic also found in various trilobites. The dorsoventrally flattened exoskeleton suggests a benthic or nektobenthic mode of life for L. deletres, as for other trilobitomorphs, and it likely used its well-developed anteriorly positioned eyes for searching out food, either to scavenge or to find prey.