The youngest ophiocistioid: a first Palaeozoic‐type echinoderm group representative from the Mesozoic
The youngest ophiocistioid: a first Palaeozoic‐type echinoderm group representative from the Mesozoic
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DOI：
10.1111/pala.12392
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发表时间：
2018-07
期刊：
影响因子：
2.6
通讯作者：
M. Reich;Tanja R. Stegemann;Imelda M. Hausmann;Vanessa Julie Roden;A. Nützel
中科院分区：
文献类型：
--
作者：
M. Reich;Tanja R. Stegemann;Imelda M. Hausmann;Vanessa Julie Roden;A. Nützel
具关节的蛇纹棘皮动物是罕见的化石，它们的系统发育地位令人费解，一直被认为是古生代棘皮动物的专属类群。除了关节的身体化石，蛇蛇总科的化石记录在其他方面依赖于孤立的微化石。然而，已经证明蛇绿类的脱节颌部元素(角齿)可以在属和种水平上进行诊断，并可以用来填补非关节化石记录中的空白。意大利晚三叠世卡西亚组被认为是世界上最重要的早中生代无脊椎动物地层之一。在南蒂罗尔米苏里纳附近的一处化石组合中发现了各种棘皮动物，其中包括一种茎类棘皮动物代表和一种新的蛇颈类动物--Lguasera triassica sp.。11月描述了新的分类单元，并将其归入舌状蛇纹藻纲。结合蛇眼总科和棘球虫总科的其他分类群，简要讨论了该群的演化史。Languasera triassica不仅是这一“古生代”棘皮类在中生代地层中的首次发现，而且还建立了世界上最年轻的角齿或蛇纹齿状牙齿的地层记录。
Articulated ophiocistioids are rare as fossils, enigmatic in terms of their phylogenetic position, and have been considered to be an exclusively Palaeozoic echinoderm group. Apart from articulated body fossils, the fossil record of Ophiocistioidea is otherwise dependent on isolated microfossils. However, it has been demonstrated that disarticulated jaw elements (goniodonts) of ophiocistioids can be diagnostic at genus and species level and can be used to fill gaps in the non‐articulated fossil record. The Late Triassic Cassian Formation of Italy is regarded as one of the most important strata of early Mesozoic invertebrates worldwide. A fossil assemblage from a locality near Misurina, South Tyrol, yielded various echinoderms, including a stem group echinoid representative and a new ophiocistioid, Linguaserra triassica sp. nov. The new taxon is described and placed within linguaserrid ophiocistioids. The evolutionary history of the group is briefly discussed in relation to other taxa of the Ophiocistioidea and Echinoidea. Linguaserra triassica not only represents the first documented occurrence of this ‘Palaeozoic’ echinoderm class from Mesozoic strata but also establishes the stratigraphically youngest record of goniodonts or ophiocistioid teeth in the world.