the qom formation, a series of shales, sandstones and carbonate deposits, is the last transgression of the sea in central iran sedimentary basin. foraminifera are one of the most important and numerous fossil groups present in the qom formation. in this study, the micropaleontology of the qom formation in three measured stratigraphic sections in south and west of tafresh (rakin, band-e-ali nagh...

A proposal is made for a classification of Oligocene European cricetids. Various problems concerning the evolu­tion Eucricetodon and Pseudocricetodon are discussed. new species described from level slightly lower than oldest occurrence genus, known so far.&nbsp

While marine records of the Eocene-Oligocene transition indicate a generally coherent response to global cooling and the growth of continental ice on Antarctica, continental rec ords indicate substantial spatial variability. Marine Eocene-Oligocene transition records are marked by an ~+1.1‰ foraminiferal δ18O shift, but continental rec ords rarely record the same geochemical signature, making b...

the asmari formation is a thick carbonate sequence in zagros foreland basin. it was deposited during oligocene – early miocene ages. in order to interpret the depositional environment and sequence stratigraphy, firuzabad section were compared with 4 sections of asmari formation in the zagros basin. four different sub environments were identified in the asmari formation based on microfacies anal...

This study documents diversity decline in a once-speciose rodent clade, the family Aplodontidae, and evaluates the potential influence of three commonly suggested controls on diversity: climate change, floral change, and competitive interactions. Aplodontids first appeared in the late Eocene, diversified during the early Oligocene, declined precipitously at the end of the Oligocene such that st...

Ocean Drilling Program holes 744A and 748B represent key sections for calibration of Southern Ocean Eocene^ Oligocene biostratigraphic zonations. Sites 744 and 748 were above the carbonate compensation depth throughout this time interval and contain good planktonic foraminiferal, calcareous nannofossil, and diatom biostratigraphic records. In particular, the Southern Ocean diatom biostratigraph...