CRITICAL-EXAMINATION OF THE DIATOM GENUS AZPEITIA - SPECIES USEFUL AS STRATIGRAPHIC MARKERS FOR THE OLIGOCENE AND MIOCENE EPOCHS Academic Article uri icon

abstract

  • Seven taxa belonging to the diatom genus Azpeitia are compared and illustrated, a key provided, and details of age and geographic distribution included. Type specimens or type collections have been examined whenever possible. One new species, A. apiculata P.A.Sims, is described; A. vetustissima var. voluta (Baldauf) Sims changed in rank, and A. nodulifera forma cyclopus (Jouse) P.A.Sims is transferred from Coscinodiscus. These taxa not only share the characteristics of the genus as a whole but share morphological similarities including only two rings of areolae on the valve mantle and exhibit close relationships to Azpeitia nodulifera (Schmidt) G.Fryxell and P.A.Sims, a living, oceanic, warm water species. Geological records indicate a limited existence of representatives of the genus during the Paleogene, with many in the Miocene, and a few in the Pliocene. -Authors

published proceedings

  • MICROPALEONTOLOGY

author list (cited authors)

  • SIMS, P. A., FRYXELL, G. A., & BALDAUF, J. G.

citation count

  • 8

complete list of authors

  • SIMS, PA||FRYXELL, GA||BALDAUF, JG

publication date

  • January 1989

publisher