The lower Ovetian Stage (lower Cambrian Stage 3) trilobite zonation in Spain and correlation with West Gondwana

摘要

New trilobites from the upper part of the Pusa Formation (base of Cambrian Stage 3) in Central Spain are studied for their systematic and biostratigraphic significance. The trilobites Proabadiella toletana n. gen. et sp., Proabadiella vidalii n. gen. et sp., and a genus et species indet. are recorded with other fossils from the lower Ovetian regional Stage and archaeocyathan Zone I, which had, until now, provided only undetermined trilobites. The Proabadiella morphology is intermediate between that of the oldest genera of trilobites belonging to the families Abadiellidae and Bigotinidae, confirming the old age inferred for the new trilobites co-occurring with the archaeocyathan assemblage. Our findings permit presenting a new trilobite zonation for the lower Ovetian regional Stage (lower Cambrian Stage 3). A correlation is proposed with the other stratigraphically lowermost trilobites recorded globally.