Boreognathus pogorevichi, a remarkable new polychaete annelid from the lower Permian of the Pechora Basin, Russia

The sclerotized jaw elements (scolecodonts) of polychaete annelids are rarely preserved as articulated jaw apparatuses. Here we describe a morphologically unusual, rather large, and symmetrical jaw apparatus, assigned to the new taxon Boreognathus pogorevichi gen. et sp. nov., from the Kungurian (lower Permian) of the Pechora Coal Basin, northern Cis-Urals, Russia. Whereas the specimen is mainly preserved as a three-dimensional external mould of the near-complete dorsal maxillary apparatus, some organic matter comprising the original jaw wall is also retained. The new taxon combines edentate, pincer-like first maxillae (MI) typical of the extant Labidognatha apparatus type with long slender carriers common in the Prionognatha type. Unlike the smooth MI, MII are consistently and prominently denticulated. The new genus represents a hitherto unknown type of polychaete jaw apparatus and is assigned to the Palaeozoic family Atraktoprionidae.