Climate models with increased levels of carbon dioxide predict that global warming causes heating in the tropics, but investigations of ancient climates based on palaeodata have generally indicated cool tropical temperatures during supposed greenhouse episodes. For example, in the Late Cretaceous and Eocene epochs there is abundant geological evidence for warm, mostly ice-free poles, but tropical sea surface temperatures are generally estimated to be only 15-23 degrees C, based on oxygen isotope palaeothermometry of surface-dwelling planktonic foraminifer shells. Here we question the validity of most such data on the grounds of poor preservation and diagenetic alteration. We present new data from exceptionally well preserved foraminifer shells extracted from impermeable clay-rich sediments, which indicate that for the intervals studied, tropical sea surface temperatures were at least 28-32 degrees C. These warm temperatures are more in line with our understanding of the geographical distributions of temperature-sensitive fossil organisms and the results of climate models with increased CO2 levels.

editors. Atlas of Paleocene Planktonic Foraminifera. Smithsonian Contributions to Paleobiol¬ ogy, number 85, 252 pages, 37 figures, 71 plates, 1999.-Sixty-seven species of Paleocene planktonic foraminifera are described and illustrated, including three species of Eoglobigerina, four species of Parasubbotina, five species of Subbotina, two species of Hedbergella, 10 species of Globanomalina, six species of Acarinina, 12 species of Morozovella, three species oilgorina, four species of Praemurica, one species of Guembelitria, one species of Globoconusa, three species of Parvulamgoglobigerina, two species of Woodringina, six species of Chiloguembelina, one species of Rectoguembelina, and four species of Zeauvigerina. Taxonomic classification of normal perforate taxa are organized according to wall texture. Spinose cancellate genera include Eoglobigerina, Parasubbotina, and Subbotina; cancellate nonspinose genera include Igorinina and Praemurica; smooth-walled genera include Hedbergella and Globanomalina', and muricate genera include Acarinina and Morozovella. Taxonomic classification of microperforate taxa (including Guembelitria, Globoconusa, Parvularugoglobigerina, Woodringina, Chiloguembelina, Rectoguembelina, and Zeauvigerina) are organized according to test morphology.Scanning electron microscope (SEM) images of type species described by Morozova in the collections of the Geological Institute, Academy of Sciences (GAN), Moscow, and the type material described by Subbotina in the collections of the All Union Petroleum Scientific Research Geological Prospecting Institute (VNIGRI), St. Petersburg, are shown on Plates 8-12. Twelve species described by Morozova, nine species described by Subbotina, and one species described by Bykova are illustrated. In addition, SEM images of 28 holotypes and two paratypes from the Smithsonian Institution collections are shown on Plates 13-17, and the lectotype for Globigerina compressa Plummer, 1926, and the neotype for Globorotalia monmouthensis Olsson, 1961, are designated and illustrated with SEM images.Paleobiogeographic maps showing the global distribution of 29 commonly occurring Paleocene taxa are included in the atlas, as well as figures showing the stratigraphic ranges of species by genus and stratigraphic first and last appearances. The biostratigraphic framework used in the atlas is the revised biostratigraphy given in Berggren et al., 1995, which is summarized in the atlas. Wall texture and morphological relationships between species and genera form the basis of phylogenetic interpretations. This is discussed in the section "Wall Texture, Classification, and Phytogeny" and is referenced to Plates 1-7.Official publication date is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Annals of the Smithsonian Institution. Series cover design: The trilobite Phacops rana Green.

We developed a Late Cretaceous sealevel estimate from Upper Cretaceous sequences at Bass River and Ancora, New Jersey (ODP [Ocean Drilling Program] Leg 174AX). We dated 11-14 sequences by integrating Sr isotope and biostratigraphy (age resolution ؎0.5 m.y.) and then estimated paleoenvironmental changes within the sequences from lithofacies and biofacies analyses. Sequences generally shallow upsection from middle-neritic to inner-neritic paleodepths, as shown by the transition from thin basal glauconite shelf sands (transgressive systems tracts [TST]), to medial-prodelta silty clays (highstand systems tracts [HST]), and finally to upperdelta-front quartz sands (HST). Sea-level estimates obtained by backstripping (accounting for paleodepth variations, sediment loading, compaction, and basin subsidence) indicate that large (Ͼ25 m) and rapid (K1 m.y.) sea-level variations occurred during the Late Cretaceous greenhouse world. The fact that the timing of Upper Cretaceous sequence boundaries in New Jersey is similar to the sea-level lowering records of Exxon Production Research Company (EPR), northwest Euro- † E-mail: kgm@rci.rutgers.edu.pean sections, and Russian platform outcrops points to a global cause. Because backstripping, seismicity, seismic stratigraphic data, and sediment-distribution patterns all indicate minimal tectonic effects on the New Jersey Coastal Plain, we interpret that we have isolated a eustatic signature. The only known mechanism that can explain such global changesglacio-eustasy-is consistent with foraminiferal ␦ 18 O data. Either continental ice sheets paced sea-level changes during the Late Cretaceous, or our understanding of causal mechanisms for global sea-level change is fundamentally flawed. Comparison of our eustatic history with published ice-sheet models and Milankovitch predictions suggests that small (5-10 ؋ 10 6 km 3 ), ephemeral, and areally restricted Antarctic ice sheets paced the Late Cretaceous global sea-level change. New Jersey and Russian eustatic estimates are typically one-half of the EPR amplitudes, though this difference varies through time, yielding markedly different eustatic curves. We conclude that New Jersey provides the best available estimate for Late Cretaceous sea-level variations.

We provide a record of global sea-level (eustatic) variations of the Late Cretaceous (99-65 Ma) greenhouse world. Ocean Drilling Program Leg 174AX provided a record of 11-14 Upper Cretaceous sequences in the New Jersey Coastal Plain that were dated by integrating Sr isotopic stratigraphy and biostratigraphy. Backstripping yielded a Late Cretaceous eustatic estimate for these sequences, taking into account sediment loading, compaction, paleowater depth, and basin subsidence. We show that Late Cretaceous sea-level changes were large (Ͼ25 m) and rapid (K1 m.y.), suggesting a glacioeustatic control. Three large ␦ 18 O increases are linked to sequence boundaries (others lack sufficient ␦ 18 O data), consistent with a glacioeustatic cause and with the development of small (Ͻ10 6 km 3) ephemeral ice sheets in Antarctica. Our sequence boundaries correlate with sea-level falls recorded by Exxon Production Research and sections from northwest Europe and Russia, indicating a global cause, although the Exxon record differs from backstripped estimates in amplitude and shape.

We improved upper Eocene to Oligocene deep‐sea chronostratigraphic control by integrating isotope (87Sr/86Sr, δ18O, δ13C) stratigraphy and magnetostratigraphy. Most previous attempts to establish the timing of isotope fluctuations have relied upon biostratigraphic age estimates which have uncertainties of 0.5 to over 4.0 m.y. Deep Sea Drilling Project (DSDP) Site 522 contains the best available upper Eocene to Oligocene magnetostratigraphic record which allows first‐order correlations of isotope records (87Sr/86Sr, δ18O, δ13C) to the Geomagnetic Polarity Time Scale (GPTS). Empirical calibrations between the 87Sr/86Sr of foraminifera and magnetochronology at Site 522 allow more precise correlation of “unknown” samples with the GPTS. For example, shallow water and high‐latitude sections may be tied into the deep‐sea record. Sr‐isotope stratigraphic resolution for the latest Eocene to Oligocene is approximately 2 m.y.