A new oryctocephalid trilobite from the Balang Formation (Cambrian Stage 4) of northwestern Hunan, South China, with remarks on the classification of oryctocephalids

摘要

A new trilobite,Longaspis paiwuensisn. gen. n. sp., from the Balang Formation (Cambrian Stage 4) in northwestern Hunan, South China, is described. This rare trilobite adds to an expanding taxonomic list of organisms recognized from the Balang Lagerst?tte, a deposit of exceptional preservation from the Cambrian.Longaspis paiwuensisis an unusually large-sized, micropygous oryctocephalid trilobite that has proparian facial sutures, pit-like lateral glabellar furrows, up to 17 thoracic segments, and a distinct medial notch in the pygidium; it lacks marginal spines.The classification of the family Oryctocephalidae is reviewed. Three subfamilies are recognized, andLongaspisn. gen. is assigned to the subfamily Oryctocarinae.