Soft-part anatomy of the Early Cambrian bivalved arthropods Kunyangella and Kunmingella: significance for the phylogenetic relationships of Bradoriida
Soft-part anatomy of the Early Cambrian bivalved arthropods Kunyangella and Kunmingella: significance for the phylogenetic relationships of Bradoriida
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DOI：
10.1098/rspb.2009.2194
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发表时间：
2010-06-22
影响因子：
4.7
通讯作者：
Sansom, Robert S.
中科院分区：
文献类型：
--
作者：
Hou, Xianguang;Williams, Mark;Sansom, Robert S.
Bradoriids是一种小型的双瓣海洋节肢动物，广泛分布于寒武纪至早奥陶世的岩石中。它们包括7个科和大约70个属，基于盾（“甲壳”）形态。本文报道了采自中国澄江早寒武世Lagerstatte的一种新的、具有保存的软体结构的扁虫化石Kunmingelladouvillei（Kunmingellidae），并首次发现了另一种具有保存的软体结构的扁虫化石Kunyangellacheni（Comptalutidae）。Kunmingella douvillei有一个10节的肢体轴承机构与uniramous第九和第十附属物和一系列的同质，显然（近端部分未保存）unspecialized postantennal biramous四肢与刚毛叶状外足。每个内足由五个足节组成。一个假定的倒数第二龄的Ky。陈尼保留了三个头和两个躯干附肢的残余，而成年人被重建为有四个头附肢。这种材料允许测试Bradoriida的亲和力。通过形态学比较和分支重建，Kunmingella在基于特征的分析中被确定为茎甲壳动物。全球简约分析恢复单系Bradoriida的姐妹集团冠甲壳类。
Bradoriids are small bivalved marine arthropods that are widespread in rocks of Cambrian to Early Ordovician age. They comprise seven families and about 70 genera based on shield ('carapace') morphology. New bradoriid specimens with preserved soft-part anatomy of Kunmingella douvillei (Kunmingellidae) are reported from the Early Cambrian Chengjiang Lagerstatte of China together with, for the first time to our knowledge, a second bradoriid species with preserved soft parts, Kunyangella cheni (Comptalutidae). Kunmingella douvillei has a 10-segmented limb-bearing body with uniramous ninth and tenth appendages and a series of homogeneous, apparently (proximal parts not preserved) unspecialized post-antennal biramous limbs with setose leaf-shaped exopods. Each endopod consists of five podomeres. A presumed penultimate instar of Ky. cheni preserves remnants of three head and two trunk appendages, and the adult is reconstructed as having four head appendages. This material allows testing of the affinity of the Bradoriida. Kunmingella is identified as a stem crustacean in character-based analyses, through both morphological comparisons and cladistic reconstructions. Global parsimony analysis recovers a monophyletic Bradoriida as the sister group to crown crustaceans.