نتایج جستجو برای: late maastrichtian
تعداد نتایج: 195833 فیلتر نتایج به سال:
An isolated dinosaur vertebra from the marine deposits of the Maastrichtian type area, near the city of Maastricht (The Netherlands), collected during the 19th century and kept in the palaeontological collection of the Museum für Naturkunde in Berlin, is described as a caudal vertebra of a hadrosaurid ornithopod. Although it cannot be identified with greater accuracy, this specimen is an additi...
Based on a review of troodontid specimens from the territories of the former Soviet Union, including new discoveries from Uzbekistan, two dental morphotypes can be distinguished among Troodontidae from the Cretaceous of Asia: (1) unserrated teeth, present in Mei from Lujiatun (China; Early Cretaceous: Hauterivian-Barremian), an unnamed taxon from Hövöör (Mongolia; Early Cretaceous: Aptian-Albia...
Studying the evolution and biogeographic distribution of dinosaurs during the latest Cretaceous is critical for better understanding the end-Cretaceous extinction event that killed off all non-avian dinosaurs. Western North America contains among the best records of Late Cretaceous terrestrial vertebrates in the world, but is biased against small-bodied dinosaurs. Isolated teeth are the primary...
A global compilation of deep-sea isotopic records suggests that Maastrichtian ocean-climate evolution was tectonically driven. During the early Maastrichtian the Atlantic intermediate-deep ocean was isolated from the Pacific, Indian, and Southern Oceans; deep water formed in the high-latitude North Atlantic and North Pacific. At the early/late Maastrichtian boundary a major reorganization of oc...
The study of planktonic foraminifera of the Ilam and Gurpi formations at Sarvestan area (SE of Shiraz) enables me to find the most standard biozones defined in mediterranean regions, especially Tethysian domain. Seven biozones were determined. Biozones I (Dicarinella concavata zone) and II (Dicarinella asymetrica zone) belong to the Ilam Formation and indicate the Late Coniacian-Early Santonian...
This study presents calcareous nannofossils biostratigraphy of the Campanian‒Danian interval at the Gurpi Formation in the southwest of Ilam Province, in the Zagros Basin. The studied sequence of the Gurpi Formation mainly consists of marly shale and limestones. The thickness of Gurpi Formation was measured as approximately 230 m. Forty-five species belonging to twenty-eight genera were recorde...
The Gurpi Formation with a thickness of 190 m at the Kouh-e sefid anticline is investigated with regard to the calcareous nannofossils. In this section, Gurpi Formation is mainly consists of shale, marls and argillaceous limestones. As a result of this study, 21 genera and 41 species of calcareous nannofossil have been recognized. Based on distribution of index species calcareous nannofossils...
the study of planktonic foraminifera of the ilam and gurpi formations at sarvestan area (se of shiraz) enables me to find the most standard biozones defined in mediterranean regions, especially tethysian domain. seven biozones were determined. biozones i (dicarinella concavata zone) and ii (dicarinella asymetrica zone) belong to the ilam formation and indicate the late coniacian-early santonian...
planktonic foraminifera are useful in determining the relative age of the upper cretaceous strata. based on distribution of planktonic foraminifera in kuh-e siah section (212 m thickness), eight biozones have been recognized including dicarinella concavata interval zone (earliest santonian), dicarinella asymetrica total range zone (santonian to earliest campanian), globotruncanita elevata parti...
A comprehensive review and study of the rich dinosaur track record of the Tremp Formation in the southern Pyrenees of Spain (Southwestern Europe) shows a unique succession of footprint localities prior to the end-Cretaceous mass extinction event. A description of some 30 new tracksites and data on sedimentary environments, track occurrence and preservation, ichnology and chronostratigraphy are ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید