短剑类(Machaeridia)属于环节动物(Annelida), 其主要特征为个体微小且左右两侧对称, 是一类相对稀少但是分布范围广泛的海相动物化石。在摩洛哥Anti-Atlas地区、中国华南、塔里木等地的奥陶系中皆有短剑类的报道, 但是研究程度相对较低。本文报道并描述了产自湖北省远安县嫘祖剖面庙坡组的短剑类标本3枚, 经初步鉴定为Plumulites sp. A (羽毛虫)和Lepidocoleus sp. (鳞鞘虫), 这项发现拓展了短剑类在华南地区的时限和地理分布, 也可看作是华南奥陶纪生物大辐射期间短剑类在扬子台地局部凹陷区域定居的反映。此外, 本文还讨论了短剑类的形态特征和分类框架, 认为早古生代的短剑类根据形态特征和骨片结构, 可以划分为3科: 羽毛虫科 Plumulitidae Jell, 1979、鳞鞘虫科Lepidocoleidae Clarke, 1896、塔形壳虫科Turrilepadidae Clarke, 1896。

Machaeridia is a poorly-known group of marine animals belonging to Annelida, and is characterized by a tiny, bilaterally symmetrical body. They are relatively rare, but widely distributed, and have been reported from the Ordovician System in Anti-Atlas of Morocco, South China, Tarim and some other regions. This paper reports and describes three specimens of Machaeridia from the Miaopo Formation at the Leizu section in Yuan’an County, Hubei Province. They are identified as Plumulites sp. A and Lepidocoleus sp. This finding expands the temporal and spatial distribution of Machaeridia in South China. These specimens represent the occurrence of Machaeridia in a shallow intra-platform depression during the Great Ordovician Biodiversification Event (GOBE). In addition, we discuss the morphological characteristics and classification of the Machaeridia, and propose that the early Paleozoic Machaeridia includes three families: Plumulitidae, Lepidocoleidae and Turrilepadidae.

国家自然科学基金(42002009)；中国地质科学院地质调查项目(DD20221829)联合资助