CUSHMAN FOUNDATION SPECIAL PUBLICATION NO. 41 P. 401-412, 2006
Chapter 13 TAXONOMY, BIOSTRATIGRAPHY, AND PHYLOGENY OF EOCENE DENTOGLOBIGERINA RICHARD K. OLSSON1, CHRISTOPH HEMLEBEN2, AND PAUL N. PEARSON3 1
Department of Geological Sciences, Busch Campus, Rutgers University, Piscataway, NJ 08854-8066, U.S.A. Email:
[email protected]. 2
Institute of Geoscience, Sand 6/7 - IfG, Kernlabor und -LagerºD-72076 Tübingen, FR Germany. Email:
[email protected]
3
School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, U.K. Email:
[email protected]
ABSTRACT The taxonomy, phylogeny, and biostratigraphy of Eocene Dentoglobigerina is reviewed. Three species are recognized as distinct, namely Dentoglobigerina
galavisi (Bermúdez), Dentoglobigerina pseudovenezuelana (Blow and Banner), and Dentoglobigerina tripartita (Koch).
INTRODUCTION
SYSTEMATIC TAXONOMY
We have found in our studies that the genera Dentoglobigerina and Globoquadrina are nonspinose which separates them taxonomically from the taxa included in the spinose family Globigerinidae. We include them in the family Globoquadrinidae Blow (1979) that has as its type species Globoquadrina dehiscens. The globoquadrinids are an important group in the Oligocene and Miocene and range to the Recent in the species Globoquadrina conglomerata. Their origin lies in the Eocene with the development of Dentoglobigerina. The globoquadrinids are characterized by having a honeycomb cancellate wall texture that is constructed by the coalescing of pustules. Larger pustules cluster in the apertural area. The ancestry appears to lie in Acarinina as discussed here and in Hemleben and Olsson, Chapter 4, this volume. The species level range-chart and phylogeny are presented in Figure 13.1.
Order FORAMINIFERIDA Eichwald, 1830 Superfamily GLOBIGERINACEAE Carpenter, Parker and Jones, 1862 Family GLOBOQUADRINIDAE Blow, 1979 Genus Dentoglobigerina Blow, 1979 TYPE SPECIES.— Globigerina galavisi Bermúdez, 1961 DESCRIPTION. Type of wall: Cancellate, Globoquadrina-type honeycomb wall texture, nonspinose. Test morphology: Trochospiral, globular, slightly lobate in outline, ultimate chamber slightly bent towards the umbilicus, forming an ill-defined apertural face; weakly pustulose except in the apertural area
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