A profound faunal reorganization occurred near the Paleocene/Eocene boundary, when several groups of mammals abruptly appeared on the Holarctic continents. To test the hypothesis that this event featured the dispersal of groups from Asia to North America and Europe, we used isotope stratigraphy, magnetostratigraphy, and quantitative biochronology to constrain the relative age of important Asian...

Two new fossil species of Nymphidae (Neuroptera) are described: Nymphes georgei sp. nov. from the Early Eocene locality at Republic, Washington, U.S.A., and Pronymphes hoffeinsorum sp. nov. from Late Eocene Baltic amber. The assignment of the new Republic species to Nymphes Leach maintains some doubt. This is the first fossil record of the genus (or one very closely related), today restricted t...

Stable and radiogenic isotopic and sedimentological data from sub-Antarctic deep sea sediment cores reveal a temporal link between changes in seawater SrrSr ratios and major episodes of late Eocene–early Oligocene climate change. The SrrSr records show two major inflections, one at 38–39 Ma near the middlerlate Eocene boundary, followed by another at 33.4 Ma. Similarly, the oxygen isotope, ice-...

Analysis of lithofacies, paleoflow directions, and sandstone petrography of upper Paleocene-lower Eocene paralic and continental sediments exposed along the transpressional suture zone of the western margin of the Indian plate indicate that the process of deformation and uplift of the carbonate shelf in this area had started by late Paleocene time. This tectonic uplift and deformation is docume...

new evidence gained by the study of foraminifera from khuzestan province in southwest iran reveals that the basal limit of the genus heterostegina is not restricted to the eocene epoch. by introducing a new species of this genus (h. rezvaninejadi), this study shows that the early appearance of this genus should be lowered down further still, at least, into the middle paleocene.

Sixteen new K-Ar dates are presented from Tasmanian and Bass Basin basalts, more than doubling the previously published number. Eight volcanic regions are described, based on boundaries established on the range of the basalt types contained in each geographic region. Volcanism occurred within the span from Eocene to Miocene (47 to 13+ Ma), but mainly within the time range Middle Eocene to Early...

Tropical South America has the highest plant diversity of any region today, but this richness is usually characterized as a geologically recent development (Neogene or Pleistocene). From caldera-lake beds exposed at Laguna del Hunco in Patagonia, Argentina, paleolatitude approximately 47 degrees S, we report 102 leaf species. Radioisotopic and paleomagnetic analyses indicate that the flora was ...

Introduction.-Following the discovery and description of a titanotherel in the Poway sands of San Diego County, continued excavation in this important Eocene horizon has produced small lots of mammalian remains. One of these included specimens of a tarsiid primate and a mixodectid. Worthy of mention is the fact that the former represents a third member of the Tarsiidae to be discovered in the e...

South America has some of the most diverse floras and insect faunas that are known, but its Cenozoic fossil record of insects and insect herbivory is sparse. We quantified insect feeding on 3,599 leaves from the speciose Laguna del Hunco flora (Chubut, Argentina), which dates to the early Eocene climatic optimum (52 million years ago) and compared the results with three well preserved, rich, an...