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.

Oxygen isotope analyses of well-preserved foraminifera from Blake Nose (30°N paleolatitude, North Atlantic) and globally distributed deep-sea sites provide a long-term paleotemperature record for the late Albian-Maastrichtian interval that is difficult to reconcile with the existence of significant Cretaceous ice sheets. Given reasonable assumptions about the isotopic composition of Cretaceous seawater, our results suggest that middle bathyal water temperatures at Blake Nose increased from ~12 °C in the late Albian through middle Cenomanian to a maximum of 20 °C during the latest Cenomanian and earliest Turonian. Bottom waters were again ~12 °C during the middle Campanian and cooled to a minimum of 9 "C during the Maastrichtian. Correlative middle bathyal foraminifera from other ocean basins yield paleotemperature estimates that are very similar to those from Blake Nose. Comparison of global bottom-water temperatures and latitudinal thermal gradients suggests that global climate changed from a warm greenhouse state during the late Albian through late Cenomanian to a hot greenhouse phase during the latest Cenomanian through early Campanian, then to cool greenhouse conditions during the mid-Campanian through Maastrichtian.

A detailed 8^*0 and 8"C stratigraphy has been generated from analysis of well-preserved Albian-early Maastrichtian foraminifera from Deep Sea Drilling Project (DSDP) Sites 511 and 327 (Falldand Plateau;-58°S-62°S paleolatitude) in the southern South Atlantic, and Cenomanian and Coniacian-Santonian foraminifera from DSDP Site 258 (Naturaliste Plateau; «»58°S paleolatitude) in the southern Indian Ocean. These results, when combined with previously published Maastrichtian stable isotope data from Ocean Drilling Program (ODP) Site 690 (Weddell Sea, '»65°S paleolatitude), provide new insight into the climatic and oceanographic history of the southern high latitudes during middle-Late Cretaceous time. The planktonic foraminifer S^^O curves reveal a gradual warming of surface waters from the Albian through the Cenomanian followed by extremely warm surface waters from the Turonian through the early Campanian. Long-term cooling of surface waters began in the late early Campanian and continued through the end of the Maastrichtian. The benthic foraminifer 8^*0 record generally parallels changes in the oxygen isotopic curves defined by shallow-dwelling planktonic foraminifera. The vertical oxygen and carbon isotopic gradients were relatively low during the Albian-Cenomanian, high from the Turonian-early Campanian, and then low during the late Campanian and Maastrichtian. Foraminiferal oxygen isotopic data from published sources and this study are averaged for each site, corrected for latitudinal changes in salinity based on modern-day surface-water values, and plotted versus paleolatitude for the late Albian, Coniacian-Santonian, and late Maastrichtian. Differences between low-and highlatitude surface-water paleotemperatures are estimated at "^14 °C during the late Albian and late Maastrichtian, but the Coniacian-Santonian reconstruction reveals only a 0-4 °C latitudinal temperature gradient. Uncertainty regarding Cretaceous salinity gradients and possible diagenetic alteration of 8'*0 values introduce error into our estimates of paleolatitudinal thermal gradients; however, apparent low equator-to-pole temperature differences could indicate much higher poleward heat transport than at present.

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Terrestrial climates near the time of the end-Cretaceous mass extinction are poorly known, limiting understanding of environmentally driven changes in biodiversity that occurred before bolide impact. We estimate paleotemperatures for the last Ϸ1.1 million years of the Cretaceous (Ϸ66.6 -65.5 million years ago, Ma) by using fossil plants from North Dakota and employ paleomagnetic stratigraphy to correlate the results to foraminiferal paleoclimatic data from four middle-and high-latitude sites. Both plants and foraminifera indicate warming near 66.0 Ma, a warming peak from Ϸ65.8 to 65.6 Ma, and cooling near 65.6 Ma, suggesting that these were global climate shifts. The warming peak coincides with the immigration of a thermophilic flora, maximum plant diversity, and the poleward range expansion of thermophilic foraminifera. Plant data indicate the continuation of relatively cool temperatures across the Cretaceous-Paleogene boundary; there is no indication of a major warming immediately after the boundary as previously reported. Our temperature proxies correspond well with recent pCO2 data from paleosol carbonate, suggesting a coupling of pCO2 and temperature. To the extent that biodiversity is correlated with temperature, estimates of the severity of end-Cretaceous extinctions that are based on occurrence data from the warming peak are probably inflated, as we illustrate for North Dakota plants. However, our analysis of climate and facies considerations shows that the effects of bolide impact should be regarded as the most significant contributor to these plant extinctions.

Ocean anoxic events were periods of high carbon burial that led to drawdown of atmospheric carbon dioxide, lowering of bottom-water oxygen concentrations and, in many cases, significant biological extinction. Most ocean anoxic events are thought to be caused by high productivity and export of carbon from surface waters which is then preserved in organic-rich sediments, known as black shales. But the factors that triggered some of these events remain uncertain. Here we present stable isotope data from a mid-Cretaceous ocean anoxic event that occurred 112 Myr ago, and that point to increased thermohaline stratification as the probable cause. Ocean anoxic event 1b is associated with an increase in surface-water temperatures and runoff that led to decreased bottom-water formation and elevated carbon burial in the restricted basins of the western Tethys and North Atlantic. This event is in many ways similar to that which led to the more recent Plio-Pleistocene Mediterranean sapropels, but the greater geographical extent and longer duration (approximately 46 kyr) of ocean anoxic event 1b suggest that processes leading to such ocean anoxic events in the North Atlantic and western Tethys were able to act over a much larger region, and sequester far more carbon, than any of the Quaternary sapropels.

As the world warms, there is a profound need to improve projections of climate change. Although the latest Earth system models offer an unprecedented number of features, fundamental uncertainties continue to cloud our view of the future. Past climates provide the only opportunity to observe how the Earth system responds to high carbon dioxide, underlining a fundamental role for paleoclimatology in constraining future climate change. Here, we review the relevancy of paleoclimate information for climate prediction and discuss the prospects for emerging methodologies to further insights gained from past climates. Advances in proxy methods and interpretations pave the way for the use of past climates for model evaluation—a practice that we argue should be widely adopted.

A B S T R A C TA compilation of foraminiferal stable isotope measurements from southern high latitude (SHL) deep-sea sites provides a novel perspective important for understanding Earth's paleotemperature and paleoceanographic changes across the rise and fall of the Cretaceous Hot Greenhouse climate and the subsequent Paleogene climatic optimum. Both new and previously published results are placed within an improved chronostratigraphic framework for southern South Atlantic and southern Indian Ocean sites. Sites studied were located between 58°and 65°S paleolatitude and were deposited at middle to upper bathyal paleodepths. Oxygen isotope records suggest similar trends in both bottom and surface water temperatures in the southern sectors of the South Atlantic and in the Indian Ocean basins. Warm conditions were present throughout the Albian, extreme warmth existed during the Cretaceous Thermal Maximum (early-mid-Turonian) through late Santonian, and long-term cooling began in the Campanian and culminated in Cretaceous temperature minima during the Maastrichtian. Gradients between surface and seafloor δ 18 O and δ 13 C values were unusually high throughout the 11.5 m.y. of extreme warmth during the Turonian-early Campanian, but these vertical gradients nearly disappeared by the early Maastrichtian.In absolute terms, paleotemperature estimates that use standard assumptions for pre-glacial seawater suggest sub-Antarctic bottom waters were ≥21°C and sub-Antarctic surface waters were ≥27°C during the Turonian, values warmer than published climate models support. Alternatively, estimated temperatures can be reduced to the upper limits of model results through freshening of high latitude waters but only if there were enhanced precipitation of water with quite low δ 18 O values. Regardless, Turonian planktonic δ 18 O values are~1.5‰ lower than minimum values reported for the Paleocene-Eocene Thermal Maximum (PETM) from the same region, a difference which corresponds to Turonian surface temperatures~6°C warmer than peak PETM temperatures if Turonian and Paleocene temperatures are estimated using the same assumptions. It is likely that warm oceans surrounding and penetrating interior Antarctica (given higher relative sea level) prevented growth of Antarctic ice sheets at all but the highest elevations from the late Aptian through late Campanian; however, Maastrichtian temperatures may have been cool enough to allow growth of small, ephemeral ice sheets. The standard explanation for the sustained warmth during Cretaceous Hot Greenhouse climate invokes higher atmospheric CO 2 levels from volcanic outgassing, but correlation among temperature estimates, proxy estimates of pCO 2 , and intervals of high fluxes of both mafic and silicic volcanism are mostly poor. This comparison demonstrates that the relative timing between events and their putative consequences need to be better constrained to test and more fully understand relationships among volcanism, pCO 2 , temperature ocean circulation, Earth's biota and the carbon cycle.