ABSTRACT The taxonomy, phylogeny, and biostratigraphy of Oligocene and early Miocene Paragloborotalia and Parasubbotina are reviewed. The two genera are closely related; Paragloborotalia was derived from Parasubbotina in the early Eocene. Parasubbotina was more diverse during the middle Eocene, while Paragloborotalia experienced considerable diversification during the mid-Oligocene and in the latest Oligocene-earliest Miocene. A significant finding has been the synonymization of Globorotalia ( Tuborotalia ) mendacis Blow, and Turborotalia primitiva Brönnimann and Resig with Globorotalia birnageae Blow. The following species from the time interval of interest are regarded as valid: Paragloborotalia acrostoma (Wezel), Paragloborotalia birnageae (Blow), Paragloborotalia continuosa (Blow), Paragloborotalia incognita (Walters) Paragloborotalia kugleri (Bolli), Paragloborotalia mayeri (Cushman and Ellisor), Paragloborotalia nana (Bolli), Paragloborotalia opima (Bolli), Paragloborotalia pseudocontinuosa (Jenkins), Paragloborotalia pseudokugleri (Blow), Paragloborotalia semivera (Hornibrook), Paragloborotalia siakensis (LeRoy), Parasubbotina hagni (Gohrbandt), and Parasubbotina varianta (Subbotina). Paragloborotalia is a long-lived group of planktonic foraminifera that spanned the early Eocene to late Miocene and provided the root stock for the evolution of multiple smooth, nonspinose, and keeled globorotaliid lineages during the Neogene. The early Oligocene forms of Paragloborotalia (nana, opima, siakensis, pseudocontinuosa ) have 4 or 5 globular chambers in the final whorl with radial spiral sutures and a broadly rounded periphery. A trend from radial to curved spiral sutures is observed in late Oligocene and earliest Miocene lineages. Most species of Paragloborotalia had wide distributions, but some were more common in tropical to warm subtropical waters (e.g., siakensis, kugleri ) and were especially dominant in the equatorial Pacific divergence zone (e.g., nana, opima, and pseudocontinuosa ) analogous to modern tropical upwelling Neogloboquadrina. Other species thrived in cool subtropical and temperate waters (e.g., acrostoma, incognita ).

ABSTRACT The taxonomy, biostratigraphy, and phylogeny of Oligocene Subbotina is discussed and reviewed. We include forms that have teeth extending into the umbilicus. A total of nine species are accepted as distinct, namely Subbotina angiporoides (Hornibrook), Subbotina corpulenta (Subbotina), Subbotina eocaena (Gümbel), Subbotina gortanii (Borsetti), Subbotina linaperta (Finlay), Subbotina minima (Jenkins), Subbotina projecta Olsson, Pearson, and Wade n. sp., Subbotina tecta Pearson and Wade, and Subbotina utilisindex (Jenkins and Orr).

Abstract Studies of foraminifera in Milan are dated back to the 1940s and have been carried out since the 1950s, when a formal course in micropaleontology was introduced within the Masters degree in geology. Since the early days, the school of Milan has conducted landmark research projects from the Mesozoic to the Quaternary with a multidisciplinary approach, contributing to the development of modern biostratigraphy, chronostratigraphy, biochronology and to the definition of the stratotypes, and playing a fundamental role in deep ocean explorations. Over the years, foraminifera, and especially planktonic foraminifera, have been extensively investigated in terms of species diversification and evolution, enhancing their validity for dating and correlating rocks, and their links to palaeoceanographic changes. An overview of the main achievements of the Milan school of micropalaeontology is presented in this paper. Among them are the delineation of the geological evolution of the Mediterranean Sea in the Neogene, including the studies that proved the Late Miocene deep-sea desiccation, the development of an integrated bio-, magneto-, chemo-and cyclostratigraphy that has provided the main basis for the geological timescale used today, and the insights into the evolution of planktonic foraminifera and into the linkages between biotic and chemostratigraphic changes that occurred during times of oceanic dysoxia and extreme climates in the Mesozoic and Palaeogene.

ABSTRACT Globigerinathekids were abundant and diverse through the middle and upper Eocene. Globigerinatheka comprises 11 species, namely G. barri Brönnimann, G. curryi Proto Decima and Bolli, G. euganea Proto Decima and Bolli, G. index (Finlay), G. korotkovi (Keller), G. kugleri (Bolli, Loeblich and Tappan), G. luterbacheri Bolli, G. mexicana (Cushman), G. semiinvoluta (Keijzer), G. subconglobata (Shutskaya), and G. tropicalis (Blow and Banner). Orbulinoides is a monotypic genus comprised solely of the short ranging species O. beckmanni (Saito). In this paper the taxonomy, phylogeny, and biostratigraphy of Globigerinatheka Brönnimann, 1952 (emended Proto Decima and Bolli, 1970) and Orbulinoides Cordey, 1968 (emended Proto Decima and Bolli, 1970) are reviewed.

ABSTRACT In this chapter we treat the taxonomy, stratigraphic distribution and phylogenetic affinities of Eocene muricate, nonspinose species of the genera Astrorotalia, Igorina and Planorotalites. Igorina had an early mid-Paleocene praemuricate ancestry and evolved at about the same time (Zone P3a; early Selandian) as the earliest morozovellids ( praeangulata, angulata); the genus became extinct in Zone E9 (early middle Eocene). Planorotalites pseudoscitula evolved in the latest Paleocene (Zone P5) from a possible morozovellid (? Morozovella occlusa ) ancestry. It evolved into the stellate, peripherally carinate, monospecific, stratigraphically restricted species A. palmerae in Zone E7 (upper lower Eocene). Seven species are recognized and discussed, namely Igorina anapetes (Blow), Igorina broedermanni (Cushman and Bermúdez), Igorina lodoensis (Mallory), Igorina tadjikistanensis (Bykova), Planorotalites capdevilensis (Cushman and Bermúdez), Planorotalites pseudoscitula (Glaessner), and Astrorotalia palmerae (Cushman and Bermúdez). Planorotalites renzi (Bolli) is confirmed as a junior synonym of P. capdevilensis. Our attempts to find an appropriate generic home for ‘ Globigerina lozanoi Colom’ have been unsuccessful for reasons explained below. We assign lozanoi provisionally to Praemurica.

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 Geological interest in Earth’s orbital variations harks back to the discovery of the Pleistocene ice ages in the 1840 by Louis Agassiz, who convinced numerous prominent geologists that the “drift” that covered much of northern Europe was not a relict of the biblical deluge but of a great ice sheet ( Imbrie and Imbrie, 1979 ). What had caused this to happen?

Abstract This work presents a detailed 87 Sr/ 86 Sr isotope curve for the 7.5–9.8 Ma time interval obtained by analyzing isotope compositions of the Orbulina universa planktonic foraminifer species from the Mediterranean Gibliscemi section (southern Sicily). The available astronomical tuning of the section provided the opportunity to assess a direct control of the Milankovitch climate cyclicity on the seawater Sr isotope changes. Results of spectral analysis suggest a linear forcing of the 400 ky eccentricity component on the 87 Sr/ 86 Sr ratios of the Mediterranean seawater. The recorded amplitude of Sr isotope 400 ky cycles ranges between ± 5.5 × 10 -5 and ± 6 × 10 -5 around the long-term trend for the Tortonian at global scale. Such a ∆ 87 Sr is of the same order of magnitude of that measured by Capo and DePaolo (1990) and Dia et al. (1991) for the Pleistocene 100 ky glacial-interglacial cycles and about two times larger than that reported for site 758 by Clemens et al. (1993) for the same periodic oscillations. Mass-balance calculations applied to our dataset suggest that periodic changes of about 100–150%in the riverine inputs can account for the amplitude oscillations of 87 Sr/ 86 Sr ratios recorded in the Mediterranean during the Tortonian,thus emphasizing the high potential of this basin as good recorder of climate-induced seawater Sr isotope changes.

Abstract High-resolution cyclostratigraphy and calcareous plankton astrobiochronology have been obtained from the latest Langhian to the earliest Tortonian of the Mediterranean. The investigated areas (Malta, Tremiti, and Sicily) are located in different geological settings, and the three studied sections show different cyclicity. Direct correlation between the Laskar 90 (1.1) solution of the insolation curve and the sedimentary cycle pattern occurring in the investigated sections showed that all the sedimentary cycles are forced dominantly by Milankovitch periodicity. This forcing is also reflected in the climate-sensitive data (CaCO 3 content, and the relative abundance of the planktonic foraminifer Globigerinoides ) as shown by the application of spectral and filtering analyses. The calibration provided astronomical ages for all the sedimentary cycles and bioevents recorded in the sections. In particular, an age of 13.59 Ma was obtained for the extinction level of Sphenolithus heteromorphus , which is the best event approximating the Langhian-Serravallian boundary and an age of 10.55 Ma for the first regular occurrence of Neogloboquadrina acostaensis , the event that better approximates the Serravallian-Tortonian boundary in the Tortonian type section.

Abstract Methodology of cyclostratigraphic analysis applied to benthic foraminifera is verified utilizing a faunal and geochemical dataset,from the Middle Miocene Ras il-Pellegrin composite section (Malta Island, central Mediterranean). Benthic data were elaborated by Q-mode varimax principal factor analysis. In this paper, spectral analysis is carried out only on two factors, which have a clear paleoecological significance: Factor 1 (loaded by Cibicidoides ungerianus and Siphonina reticulata ), indicative of oxic bottom waters, and Factor 2 (loaded by Bulimina elongata group), indicative of oxygen-stressed conditions. Results of these analyses show that Factor 1 and Factor 2 curves are,respectively, in and out of phase with maxima of the eccentricity (100 d 400 ky). We utilize the 3D paleocenographic model of Bellanca et al. (2002) as reference for the Middle Miocene Mediterranean circulation and focus our attention on the Mediterranean Intermediate water, characterized by hydrographic and hydrodynamic features similar to those presently recorded in the Levantine Intermediate Water (LIW). Consequently, we suppose that Middle Miocene Mediterranean Intermediate Water, here defined as proto-MIW, played a role similar to that of present Mediterranean Intermediate Water (MIW). Following this hypothesis, Factor 1, which is indicative of oxic bottom waters, is interpreted as a tracer of high production of proto-MIW, during periods of high eccentricity and, probably, precession minima, characterized by coldest winter seasons. These results point out a direct link between selected benthic species, long-term astronomical forcing, and deep-water response and provide a useful tool for astronomical calibration of geologic time and for paleoceanographic reconstructions.

Abstract The mid-Cretaceous (Albian) deep-water sediments (coccolith-globigerinacean marls) of the Umbria-Marche Apennines show complex rhythmic bedding. We integrated earlier work with a time-series study of a digitized and image-processed photographic log of the Piobbico core. A drab facies is viewed as recording normal stratified conditions, and a red facies as the product of downwelling warm saline (halothermal) waters. Both are pervaded by orbital (Milankovitch) rhythms. These reflect fluctuations in the composition and abundance of the calcareous plankton in the upper waters. The drab facies is overprinted by redox oscillations on the bottom, including episodic precessional anaerobic pulses (PAPs). Contrasts between the individual beds representing the alternate phases of the precessional rhythm rose and fell with orbital eccentricity, in the classical pattern of Berger’s climatic precession or precession index curve, varyingly complicated by the obliquity rhythm. We conclude that greenhouse oceans in general, and perhaps this area in particular, were very sensitive to orbital forcing. Our count of 29 406-ky eccentricity cycles yields an Albian duration of 11.8 ± 0.4 My.