Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, Yunnan Province, People's Republic of China.
Proc Biol Sci. 2010 Jun 22;277(1689):1835-41. doi: 10.1098/rspb.2009.2194. Epub 2010 Feb 24.
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 Lagerstätte 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.
Bradoriids 是小型双壳海洋节肢动物,广泛分布于寒武纪至早奥陶世的岩石中。它们基于盾牌(“甲壳”)形态分为七个科和大约 70 个属。在中国早寒武世澄江生物群中报道了具有保存完好的软体制解剖结构的新 Bradoriid 标本 Kunmingella douvillei(Kunmingellidae),这是首次报道具有保存完好的软体制解剖结构的第二种 Bradoriid 物种 Kunyangella cheni(Comptalutidae)。Kunmingella douvillei 具有 10 节肢带肢体的身体,第九和第十个附肢具有单叉,一系列同质的、显然(未保存近节部分)无特化的后触角双叉肢体,具有带刺的叶状外肢。每个内肢由五个足节组成。一个假定的 Ky. cheni 幼虫期保存了三个头部和两个躯干附肢的残余物,而成体被重建为具有四个头部附肢。这些材料允许对 Bradoriida 的亲缘关系进行测试。通过形态比较和系统发育重建,在基于特征的分析中,将 Kunmingella 鉴定为具有甲壳纲特征的原虾。全球简约分析恢复了一个单系的 Bradoriida,作为冠甲壳动物的姊妹群。