The Middle Eocene Climatic Optimum (MECO; ~40 Ma), which interrupted for ~500–600 kyr the long-term cooling trend culminating at Eocene/Oligocene boundary, still requires a comprehensive understanding of biotic resilience. Here we present high-resolution integrated foraminiferal and calcareous nannofossil study across MECO from expanded continuous Tethyan Baskil section (eastern Turkey) that of...

F oraminifers are single-celled, testate protists with a rich geologic record spanning at least 500 million years of Earth’s most recent history. Their abundance, diversity, and diagnostic distribution patterns make them very useful to Earth scientists for purposes of relative age determination, correlation from one locality to another, and paleoenvironmental reconstructions. Benthic foraminife...

Shells of planktonic foraminifera recovered from marine sediments provide a multitude of important palaeoproxies. Most of these proxies are based on the assumption that each morphospecies of planktonic foraminifera represents a genetically continuous species with a unique habitat. Recent discovery of hitherto hidden genetic diversity among modern planktonic foraminifera has significant repercus...

Phylogenetic analysis of small and large subunits of rDNA genes suggested that Foraminifera originated early in the evolution of eukaryotes, preceding the origin of other rhizopodial protists. This view was recently challenged by the analysis of actin and ubiquitin protein sequences, which revealed a close relationship between Foraminifera and Cercozoa, an assemblage of various filose amoebae a...

Studies of the effects of the Central American Seaway’s closure on microfossil taxa and stable isotopes of foraminifera previously addressed the timing of emplacement of the Caribbean–tropical eastern Pacific sill, changes in marine nutrients, evolutionary and paleobiogeographic events associated with closure, and rates of uplift in Central America. However, there have been no quantitative stud...

The litho-and biostratigraphy of Upper Cretaceous (Gurpi Formation) has been investigated within a well-exposed section at the northern limb of Pey zard anticline, Abnow area, Southern Iran. The studied section consists mainly of grey marl, calcareous pyritic shale, and argillaceous limestones. The Formation unconformably overlies Sarvak Formation and the Tarbur Formation overlies it unconforma...

Foraminifera are one of the largest groups of unicellular eukaryotes with probably the best known fossil record. However, the origin of foraminifera and their phylogenetic relationships with other eukaryotes are not well established. In particular, two recent reports, based on ribosomal RNA gene sequences, have reached strikingly different conclusions about foraminifera's evolutionary position ...