A new radiodontan oral cone with a unique combination of anatomicalfeatures from the early Cambrian Guanshan Lagerstätte, eastern Yunnan, South China
A new radiodontan oral cone with a unique combination of anatomicalfeatures from the early Cambrian Guanshan Lagerstätte, eastern Yunnan, South China
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一种新的放射牙菌口腔锥体，具有独特的解剖特征组合，来自华南云南东部的早寒武世关山拉格斯特特
DOI：
10.1017/jpa.2017.77
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发表时间：
2017
影响因子：
1.4
通讯作者：
Zhu M.Y.
中科院分区：
文献类型：
--
作者：
Zeng H.;Zhao F.C.;Yin Z.J.;Zhu M.Y.
放射齿类，包括anomalocaridids和他们的盟友，是神秘的茎群真节肢动物，是最古老的顶端巨型食肉动物已知的化石记录。大多数关于其摄食行为的研究都强调了其多样性和丰富的捕食额附肢，而这些动物开口周围的口锥却很少受到关注。目前已知三种口锥形态型，分别来自Anomalocaris Whiteaves，1892，Peytoia Walcott，1911和Hurdia Walcott，1912。本文报道了在滇东五龙箐组官山组（寒武系2统4期）中发现的一种新的放射齿动物口锥。这口锥是独特的结合在Peytoia/Hurdia和Anomalocaris中看到的特征。它拥有一个Peytoia/Hurdia型的“四辐”结构，包括一个32板的外环，由四个垂直排列的大板和28个小板组成，除了板表面上的沟状褶皱和鳞片状节点之外，只有在Anomalocaris中才能看到。关山口锥作为一个中间形态型，提高了我们对radiodontan口锥的发生和形态差异的认识，阐明了未来可能的可变radiodontan摄食机制的研究，并揭示了这些特殊摄食结构可能的进化转变。在未来的研究中，除了额附肢之外，对其他身体部位的新知识可能会提高目前放射性牙釉质发育的分辨率。
The radiodontans, including anomalocaridids and their allies, are enigmatic stem-group euarthropods and are the most ancient apex giant predators known from the fossil record. Most studies on their feeding behaviors have emphasized their diverse and abundant raptorial frontal appendages, while the oral cone surrounding the mouth opening in these animals has attracted less attention. At present, three oral cone morphotypes are known, from Anomalocaris Whiteaves, 1892, Peytoia Walcott, 1911, and Hurdia Walcott, 1912, respectively. In this paper, we report on a novel form of radiodontan oral cone from the Guanshan Lagerstätte (Cambrian Series 2, Stage 4) in the Wulongqing Formation, eastern Yunnan, South China. This oral cone is unique in combining features seen in Peytoia/Hurdia and Anomalocaris. It possesses a Peytoia/Hurdia-type ‘tetraradial’ configuration comprising a 32-plate outer ring that consists of four perpendicularly arranged large plates and 28 small plates, in addition to furrowed folds and scale-like nodes on plate surfaces otherwise seen only in Anomalocaris. As an intermediate morphotype, the Guanshan oral cone improves our understanding of the occurrence and morphological disparity of radiodontan oral cones, illuminates future investigations on potentially variable radiodontan feeding mechanisms, and reveals possible evolutionary transformations of these peculiar feeding structures. The resolution of current radiodontan phylogeny would be potentially improved by new knowledge on other body parts apart from frontal appendages in future studies.