New scolecodonts (polychaeta, annelida) from the Late Silurian of Yunnan, South China

Scolecodonts are the fossilised jaw apparatus of polychaetes, with fossil records dating back to the Late Cambrian. However, they are commonly found in Ordovician, Silurian and Devonian strata. Here, we describe three species— Langeites aff. glaber, Langeites sp., and Oenonites spp. from the Miaogao Formation in Yiliang, Yunnan, South China. A comparative morphological study on the maxillary apparatus of the family Paulinidae and the extant members of Eunicidae and Onuphidae was conducted. This study aims to evaluate evolutionary changes in the maxillary apparatus, particularly the first maxilla, within the eulabidognatha-type apparatus. To infer their palaeoecology, Langeites aff. glaber and Langeites sp. were compared with modern species of Eunicidae and Onuphidae based on their complex maxillary apparatus. The similarity between these fossil and extant taxa suggests that Langeites retained similar feeding habits over time. These scolecodonts represent a new record for the Late Silurian of South China, and extend the geographical range of the genus Langeites. As a genus restricted to the Silurian, Langeites has potential applications in stratigraphic correlation for the Late Ludlow to Early Pridoli.