نتایج جستجو برای: late maastrichtian
تعداد نتایج: 195833 فیلتر نتایج به سال:
The Azhdarchidae have come to be known as the most diverse clade of Late Cretaceous pterosaurs and largest flying creatures in existence. Since erection taxon nearly four decades ago, many partial specimens been referred it from Early Jurassic, but none these identifications can confirmed. comprehensive phylogenetic analysis taxonomy Pterosauria is presented, evolutionary history reviewed. As c...
Leptomaria antipodensis and Leptomaria hickmanae are described from the Upper Cretaceous [Maastrichtian] Lopez de Bertodano Formation, Seymour Island, and represent the first Mesozoic records of the family Pleurotomariidae from Antarctica. Leptomaria stillwelli, L. seymourensis, Conotomaria sobralensis and C. bayeri, from the Paleocene [Danian], Sobral Formation, Seymour Island, are described a...
Cranial Endocast of the Lambeosaurine Hadrosaurid Amurosaurus riabinini from the Amur Region, Russia
Information on the structure of the brain of the lambeosaurine hadrosaurid dinosaur Amurosaurus riabinini, from the Late Maastrichtian of Blagoveschensk, Far Eastern Russia, is presented based on endocranial casts. The endocasts are compared with physical and digital endocasts of other dinosaurs. The olfactory tract was large. The cerebral hemispheres are enlarged and round, illustrating the im...
The historical view of a uniformly warm Cretaceous is being increasingly challenged by the accumulation of new data hinting at the possibility of glacial events, even during the Cenomanian-Turonian (∼95 Myr ago), the warmest interval of the Cretaceous. Here we show that the palaeogeography typifying the Cenomanian-Turonian renders the Earth System resilient to glaciation with no perennial ice a...
BACKGROUND Rhabdodontid ornithopod dinosaurs are characteristic elements of Late Cretaceous European vertebrate faunas and were previously collected from lower Campanian to Maastrichtian continental deposits. Phylogenetic analyses have placed rhabdodontids among basal ornithopods as the sister taxon to the clade consisting of Tenontosaurus, Dryosaurus, Camptosaurus, and Iguanodon. Recent studie...
An abrupt global warming event has been recorded in many parts of the world in sediments of Latest Maastrichtian age between 65.45-65.10 Ma. This warm event was documented here at a section near Ziyarat-kola in Central Alborz based on analysis of planktonic foraminifera. An unusual abundance of normally large-size species such as Globotruncana arca, Globigerinelloides subcarinatus, Pseudoguembe...
Many palaeobiological analyses have concluded that modern birds (Neornithes) radiated no earlier than the Maastrichtian, whereas molecular clock studies have argued for a much earlier origination. Here, we assess the quality of the fossil record of Mesozoic avian species, using a recently proposed character completeness metric which calculates the percentage of phylogenetic characters that can ...
In the previous paper, geological ages of Late Cretaceous, Paleocene, late Middle to Eocene, Oligocene and early Early Miocene were confirmed at first time, based on occurrences both age diagnostic larger foraminifera associated planktonic foraminifera, from Sashida Limestone included basalt pebbles, Sashida, Kamo-Gun, south Izu Peninsula. Therefore, was made up clastic carbonate rocks various ...
In the present study, the sediments of the Gurpi Formation in the Jafarabad section located in the southeast of Ilam were examined from the point of view of calcareous calcareous nannofossils. The sediments of the upper part of Gurpi Formation with a thickness of about 42 m are composed of limy marl sediments. In this study, 34 species belonging to 22 genera from the group of calcareous nannopl...
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