Articles | Volume 22, issue 2
J. Micropalaeontol., 22, 141–146, 2003
https://doi.org/10.1144/jm.22.2.141
J. Micropalaeontol., 22, 141–146, 2003
https://doi.org/10.1144/jm.22.2.141

  01 Nov 2003

01 Nov 2003

Coiling direction in Globigerina bulloides of Middle Miocene age

Malgorzata Gonera1, Tadeusz Marek Peryt2, and Tomasz Durakiewicz3,4 Malgorzata Gonera et al.
  • 1Instytut Ochrony Przyrody PAN, Al. A. Mickiewicza 33, 31-120 Kraków, Poland
  • 2Państwowy Instytut Geologiczny, Rakowiecka 4, 00-975 Warszawa, Poland
  • 3Instytut Fizyki UMCS, Plac M. Curie-Sklodowskiej 1, 20-031 Lublin, Poland
  • 4Los Alamos National Laboratory, Los Alamos, NM 87545, USA

Abstract. Detailed analysis of the early evolutionary stage of Globigerina bulloides in Middle Miocene calcareous nannoplankton zones NN5 and NN6 shows no preference for sinistral or dextral coiling patterns despite seawater temperature variations (as inferred from stable isotope analyses of foraminifer shells). Accordingly, coiling direction was proportional or biased to sinistral.