The latest Ordovician to earliest Silurian graptolite Avitograptus avitus is important in the biostratigraphy of the Ordovician–Silurian boundary interval. Two additional species of Avitograptus are described from the sponge-dominated Anji Biota of the Upper Ordovician Wenchang Formation (Metabolograptus persculptus Biozone) of Zhejiang Province, South China. One species, Avitograptus akidomorphus new species, is new; the other, Avitograptus acanthocystus new combination, which was previously placed in Climacograptus, is herein assigned to Avitograptus. The former species may represent the ancestral akidograptid because it is identical in thecal form to Akidograptus, but differs in the development of the proximal end. The evolutionary changes from Avitograptus avitus to Akidograptus and Parakidograptus involved distal movement of the origins of th11 and th12, thecal elongation, and greater outward inclination of the thecal walls.UUID: http://zoobank.org/81c433a0-9069-48d2-ae72-1267400cbf77.

中文翻译：

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华南赫南特（奥陶纪上层）安吉生物群的飞龙种（Graptolithina）及Akidograptus和Parakidograptus的进化

最新奥陶纪至最早志留纪笔石飞鸟在奥陶纪-志留纪边界层段的生物地层学中很重要。另外两种飞龙描述于上奥陶统文昌组以海绵为主的安吉生物群（变形金刚浙江省，华南生物区。一种，Avitograptus akidomorphus新物种，是新的；另一个，棘囊鲎新组合，之前放置在鸬鹚, 在此分配给飞龙. 前一种物种可能代表祖先的akidograptid，因为它的鞘形式与秋龙属，但在近端的发育上有所不同。进化变化从飞鸟到秋龙属和翼龙涉及 th1 起点的远端运动1和th12，鞘膜伸长和鞘壁更大的向外倾斜。UUID：http://zoobank.org/81c433a0-9069-48d2-ae72-1267400cbf77.