ABSTRACT The taxonomy, phylogeny and biostratigraphy of the Oligocene Globanomalinidae (comprising the genera Pseudohastigerina and Turborotalia ) is reviewed. Members of the Family have a macroperforate, nonspinose, smooth to weakly cancellate wall. Extinctions in the late Eocene left the Family restricted to just a few surviving forms which themselves became extinct in the early Oligocene. The group is very useful for biostratigraphy, with the extinctions of Pseudohastigerina naguewichiensis and Turborotalia ampliapertura providing the lowest two biozone boundaries of the Oligocene. The following species are recognized as valid: Pseudohastigerina micra (Cole), Pseudohastigerina naguewichiensis (Myatliuk), Turborotalia ampliapertura (Bolli), and Turborotalia increbescens (Bandy).

ABSTRACT The taxonomy, phylogeny and biostratigraphy of Eocene Turborotalia is reviewed. A total of nine species are recognized as distinct, namely Turborotalia altispiroides Bermúdez, 1961, Turborotalia ampliapertura (Bolli, 1957), Turborotalia cerroazulensis (Cole, 1928), Turborotalia cocoaensis (Cushman, 1928), Turborotalia cunialensis (Toumarkine and Bolli, 1970), Turborotalia frontosa (Subbotina, 1953), Turborotalia increbescens (Bandy, 1949), Turborotalia pomeroli (Toumarkine and Bolli, 1970), and Turborotalia possagnoensis (Toumarkine and Bolli, 1970). We support the view of Samuel and Salaj (1968) and Toumarkine and Bolli (1970) that Turborotalia frontosa, an enigmatic species that evolved in the early Eocene, was the first true member of the genus. Despite having a more globular morphology, T. frontosa shares several characters with other members of the genus, including its pustulose wall which has a strong tendency to defoliate, and high arched aperture. There is also a complete morphological intergradation between T. frontosa and later species of the genus. Studies of wall texture and ontogeny (Hemleben and Olsson Chapter 4, this volume) reveal the similarity of neanic T. frontosa with adult Globanomalina australiformis, a high latitude species that first evolved in the late Paleocene. We hypothesize that T. frontosa evolved from Globanomalina australiformis by the heterochronic process of hypermorphosis, and hence include Turborotalia in the Family Hedbergellidae.

ABSTRACT Analysis of the wall structures of Eocene normal perforate planktonic foraminifera permits the separation of groups of taxa that have significance for phylogeny and classification. The following spinose wall textures are recognized: sacculifer -type, ruber -type, sacculifer/ruber -type, Turborotalita -type, bulloides -type, and Clavigerinella -type. The Clavigerinella -type is subdivided into a Hantkenina -subtype in which spines have apparently been lost, except perhaps in some juvenile stages. Nonspinose wall texture includes smooth-walled, muricate, Globoquadrina -type, Turborotalia -type, and microperforate. The Globoquadrina -type is believed to have originated from the muricate genus Acarinina in the development of Dentoglobigerina, and the Turborotalia -type originated from the smooth-walled genus Globanomalina in the development of the genus Turborotalia. Diagenetic alterations of primary wall texture include dissolution, degradation of layered wall structure, and recrystallization. This has implications for the recognition/interpretation of wall texture.

ABSTRACT The taxonomy of Oligocene planktonic foraminifera of uncertain affinity are discussed and reviewed in this chapter. The following taxa are considered Problematica: Acarinina inaequiconica Subbotina, Globigerina brevis Jenkins, Globigerina ? grata Todd, Globigerina khadumica Bykova, Globigerina postcretacea Myatliuk, Globigerina pseudoedita Subbotina, Globigerina spirata Bornemann, Globigerina stainforthi Hofker, Globigerinella evoluta Subbotina, Globigerinella liverovskae Bykova, Globigerinella praemicra Subbotina, Globigerinella subangulata Ivanova, Globigerinoides inusitatus Jenkins, Globorotalia denseconnexa Subbotina, Globorotalia hexacamerata Subbotina, Globorotalia tetracamerata Subbotina, Guembelina plana Ivanova, Guembelina pseudostriata Ivanova, Subbotina droogeri Myatliuk, Subbotina vialovi Myatliuk, Turborotalia bannerblowi Blaicher, and Turborotalia czeczvaensis Myatliuk. Our understanding of each of these taxa, along with many new SEMs of the holotypes, are presented.