Variation inGloborotalia miozea(Foraminiferida) from the New Zealand neogene

Abstract

Shape in Clifdenian-Opoitian (lower Miocene-Pliocene) populations of Globorotalia miozea Finlay is studied using amplitudes of Fourier series fitted to the axial profile of the shell. In G. miozea conoidea (Waiauan-Tongaporutuan) the axial profile is typically conical. In G. miozea miotumida (Waiauan-Opoitian) it is biconvex but relatively more inflated than in G. miozea miozea (Altonian-Kapitean?). Globorotalia miozea conoidea represents a modest shift towards truncatuline architecture in a predominantly menardine lineage. Encrustation occurs in all three subspecies. The upper Miocene history of the lineage is unclear. In Waiauan rocks G. miozea miozea appears to have been replaced by G. miozca conoidea and G. miozea miotumida, taxa that were geographically sympatric. However, a Kapitean population is closely similar in form to G.