Article: Cambrian origins of the odontopleurid trilobites

Type and topotype material of middle and upper Cambrian odontopleuracean trilobites is described from the Soviet Union and new family and generic diagnoses are given. Belovia, Acidaspidina, and Eoacidaspis are assigned to the Family Eoacidaspididae, Acidaspides and Acidaspidella to the Odontopleuridae. Holaspid cranidia of Acidaspides resemble those of early Ordovician Primaspis (Odontopleurinae), pre-holaspid growth stages resemble certain Miraspidinae, and Acidaspidella resembles Leonaspis. This confirms the view of Whittington that Primaspis and Leonaspis are among the root-stocks of the Odontopleurinae. The range of the Odontopleuridae is middle Cambrian to upper Devonian making this one of the longest living trilobite families.