Chapter 16: TAXONOMY, BIOSTRATIGRAPHY, AND PHYLOGENY OF EOCENE MICROPERFORATE PLANKTONIC FORAMINIFERA (JENKINSINA, CASSIGERINELLOITA, CHILOGUEMBELINA, STREPTOCHILUS, ZEAUVIGERINA, TENUITELLA, AND CASSIGERINELLA) AND PROBLEMATICA (DIPSIDRIPELLA)
Published:August 31, 2006
Brian T. Huber, Richard K. Olsson, Paul N. Pearson, 2006. "TAXONOMY, BIOSTRATIGRAPHY, AND PHYLOGENY OF EOCENE MICROPERFORATE PLANKTONIC FORAMINIFERA (JENKINSINA, CASSIGERINELLOITA, CHILOGUEMBELINA, STREPTOCHILUS, ZEAUVIGERINA, TENUITELLA, AND CASSIGERINELLA) AND PROBLEMATICA (DIPSIDRIPELLA)", Atlas of Eocene Planktonic Foraminifera, Paul N. Pearson, Richard K. Olsson, Brian T. Huber, Christoph Hemleben, William A. Berggren
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The taxonomy, phylogeny and biostratigraphy of Eocene microperforate taxa classified under Jenkinsina, Cassigerinelloita, Chiloguembelina, Zeauvigerina, Tenuitella, and Cassigerinella is presented. A total of 20 microperforate species are recognized in Eocene planktonic foraminifer assemblages, namely: Jenkinsina columbiana (Howe), Jenkinsina triseriata (Terquem), Cassigerinelloita amekiensis Stolk, Chiloguembelina crinita (Glaessner), Chiloguembelina cubensis (Palmer), Chiloguembelina ototara (Finlay), Chiloguembelina parallela Beckmann, Chiloguembelina trinitatensis (Cushman and Renz), Chiloguembelina wilcoxensis (Cushman and Ponton), Streptochilus martini (Pijpers), Zeauvigerina aegyptiaca Said and Kenawy, Zeauvigerina lodoensis Martin, Zeauvigerina parri Finlay, Zeauvigerina zelandica Finlay, Tenuitella gemma (Jenkins), Tenuitella insolita (Jenkins), Tenuitella patefacta Li, Tenuitella praegemma Li, Cassigerinella chipolensis (Cushman and Ponton), and Cassigerinella eocaenica Cordey.
Two species are placed in Problematica pending clarification of their taxonomic position. These are Dipsidripella danvillensis (Howe and Wallace) and Dipsidripella liqianyui Huber and Pearson n. sp. Oxygen isotope signatures of D. danvillensis are more similar to co-occurring benthic species than to planktonic species, and carbon isotope ratios are significantly more negative than co-occurring benthic and planktonic species. Identification of a monolamellar wall microstructure in D. danvillensis indicates that this species is unrelated to the Globigerinaceae or Hetero-helicacea, and its restricted occurrence in neritic biofacies suggests that it lived part or most of its life below the thermocline. The wall microstructure and habitat preference of D. liqianyui n.sp. cannot be determined because of the inadequate preservation and limited distribution of specimens studied thus far. Observation of a monolamellar wall structure in J. columbiana, T. praegemma, T. gemma, and T. insolita indicates that the Eocene microperforate species may share a common ancestor.
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Atlas of Eocene Planktonic Foraminifera
The biostratigraphy, taxonomy and phylogenetic systematics of Eocene planktonic foraminifera are treated in an illustrated atlas format. Scanning electron micrographs of the type specimens of 114 species are illustrated for the first time, providing new insight to the shell architecture and wall texture, particularly for species that were poorly illustrated when first described. The phylogenetic relationships of all species of Eocene planktonic foraminifera are reviewed. Analysis of wall textures, based on well-preserved material (much of which is illustrated for the first time) provides the basis for the higher taxonomy. Accordingly, Eocene normal perforate planktonic foraminifera are divided into the Families Globigerinidae, Hantkeninidae, Truncorotaloididae, Globoquadrinidae and Hedbergellidae. Eocene microperforate species, which are less well known, are placed in the Families Guembelitriidae, Chiloguembelinidae, Hetero-helicidae, and Cassigerinellidae.
The biostratigraphic occurrences of all species of Eocene planktonic foraminifera are reviewed. Recently proposed modifications to the standard (sub)tropical and Antarctic zonations (the so-called “E-zones” of Berggren and Pearson, 2005 and “AP-zones” of Huber and Quillévéré, 2005) are followed in this atlas.
One hundred and sixty-eight species of Eocene planktonic foraminifera are recognized, including 5 species of Catapsydrax, 2 species of Globorotaloides, 1 species of Guembelitrioides, 2 species of Paragloborotalia, 6 species of Parasubbotina, 1 species of Pseudoglobigerinella Olsson and Pearson n. gen., 1 species of Globigerina, 5 species of Globoturborotalita, 15 species of Subbotina, 2 species of Turborotalita, 11 species of Globigerinatheka, 1 species of Orbulinoides, 5 species of Clavigerinella, 1 species of Cribrohantkenina, 10 species of Hantkenina, 28 species of Acarinina, 4 species of Morozovelloides Pearson and Berggren n. gen., 16 species of Morozovella, 1 species of Astrorotalia, 4 species of Igorina, 2 species of Planorotalites, 1 species questionably assigned to Praemurica, 3 species of Dentoglobigerina, 5 species of Globanomalina, 1 species of Planoglobanomalina Olsson and Hemleben n. gen., 4 species of Pseudohastigerina, 9 species of Turborotalia, 6 species of Chiloguembelina, 1 species of Streptochilus, 4 species of Tenuitella, 2 species of Cassigerinella, 1 species of Cassigerinelloita, 2 species of Jenkinsina, 4 species of Zeauvigerina, and 2 species of Dipsidripella.
The following taxa are named for the first time; the genera Pseudoglobigerinella (Olsson and Pearson n. gen.; type species Globigerina wilsoni bolivariana Petters), Morozovelloides (Pearson and Berggren n. gen.; type species Globorotalia lehneri Cushman and Jarvis), Planoglobanomalina (Olsson and Hemleben n. gen.; type species Planoglobanomalina pseudoalgeriana Olsson and Hemleben n. sp.); and the species Parasubbotina pseudowilsoni Olsson and Pearson n. sp., Paragloborotalia griffinoides Olsson and Pearson n. sp., Globorotaloides eovariablis Huber and Pearson n. sp., Globorotaloides quadrocameratus Olsson, Pearson and Huber n. sp., Globoturborotalita bassriverensis Olsson and Hemleben n. sp., Turborotalita praequinqueloba Olsson and Hemleben n. sp., Hantkenina singanoae Pearson and Coxall n. sp., Acarinina mcgowrani Wade and Pearson n. sp., Acarinina pseudosubsphaerica Berggren and Pearson n. sp., and Planoglobanomalina pseudoalgeriana Olsson and Hemleben n. sp.