The Classification and Evolution of Cretaceous Planktonic Foraminifera. Part I: The Superfamily Hedbergelloidea
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José Francisco Longoria [1] ; Martha Alicia Gamper [1]
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[1] Universidad Nacional Autónoma de México
Universidad Nacional Autónoma de México
México
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- Localización: Revista española de micropaleontología, ISSN 0556-655X, Nº. Extra 0, 1975, págs. 61-96
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
The classification of the Cretaceous Planktonic foraminifera is reviewed. The Superfamily Hedbergelloidea is proposed to include all the Cretaceous trochospiral and planispiral planktonic foraminifera which are connected during their phylogenesis. The apertural structures of this group of foraminifera are considered to be of great importance for their taxonomy at the family level. The apertural structures are illustrated in detaile with Scanning Electron micrographs of well- preserved specimens representatives of each family-group. The Hedbergellidae only possess imperforate flaps around the primary aperture. Portici are characterisite of the Marginotruncanidae. Tegilla are only present in all the members of the Globotruncanidae. The Abathomphalidae are characterized by having umbilical techo. The umbilical cover-plate is only observed in the Ticinellidae. Secondary apertures are restricted to the Rotaliporidae. The significance of the evolution of the apertural structures is discussed. The Hedbergelloidea is considered as a natural group and their phylogenesis is interpreted.
