The Upper Bajocian ammonite Strenoceras in Chile: first circum-Pacific record of the subfurcatum Zone

Abstract

The first Strenoceras [cf. latisulcatum (Qu.)] in the Americas and the entire circumPacific was found in the classical section of Caracoles in Antofagasta province, N. Chile. Its stratigraphic position is the boundary of the Torcazas and Mina Chica Formations i.e. directly superjacient to the Stepanoceras lleds (with S. chilense etc.). Since Strenoceras has only been known from the subfurcatum Zone, basal Upper Bajocian of Europe and N.W. Africa, this standard zone is now extended to the S.E. Pacific. The Associated Caomites aff. deslongchampsi also indicates pot-Lower Bajocian age and Tethyan affinities.