a succession of late campanian- early maastrichtian is analyzed from gurpi formation with regard to the calcareous nannofossils. correlation matrix was applied for the first time to the entire nannofossil assemblage to reconstruct environmental conditions. a detailed quantitative calcareous nannofossil analyses is performed on samples in order to further investigate the climate events, and inte...

The fossil record of centrosaurine ceratopsids is largely restricted to the northern region of western North America (Alberta, Montana and Alaska). Exceptions consist of single taxa from Utah (Diabloceratops) and China (Sinoceratops), plus otherwise fragmentary remains from the southern Western Interior of North America. Here, we describe a remarkable new taxon, Nasutoceratops titusi n. gen. et...

The Late Cretaceous 'greenhouse' world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic ge...

The paper presents original and published data of radioisotope dating volcanic rocks the Magellan Seamounts. These available geological materials allow us to distinguish five major complexes different ages in guyots Seamounts: 1 — Late Jurassic-Early Cretaceous (earliest Cretaceous); 2 Early (Apt-Albian); 3 (Late Cenomanian-Turonian- Campanian); 4 Campanian-Maastrichian); 5 Cenozoic. Each these...

BACKGROUND During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known onl...

The well-sampled Late Cretaceous fossil record of North America remains the only high-resolution dataset for evaluating patterns of dinosaur diversity leading up to the terminal Cretaceous extinction event. Hadrosaurine hadrosaurids (Dinosauria: Ornithopoda) closely related to Edmontosaurus are among the most common megaherbivores in latest Campanian and Maastrichtian deposits of western North ...

A calcareous nannofossils biostratigraphic study has been carried out on the chalky limestones located in South Gorgan, north of Iran. The study is aimed at determining the age and nannofossil biozonations of the well. The samples were prepared using smear slide technique. Thirty seven calcareous nannofossils species were identified and used to make biostratigraphic zonations and dating of the ...

in present study, diversity and relative abundance of calcareous nannofossils of the boundary between abtalkh and neyzar formations in dobaradar, kalat and chahchaheh sections were studied. taxonomical studies of calcareous nannofossils in the studied areas led to identification of 24 species in dobaradar, 27 species in kalat and 32 species in chahchaheh sections. based on identified nannofossi...