نتایج جستجو برای: aptian
تعداد نتایج: 457 فیلتر نتایج به سال:
Abstract The early to mid-Aptian was punctuated by episodic phases of organic-carbon burial in various oceanographic settings, which are possibly related massive volcanism associated with the emplacement Ontong Java, Manihiki, and Hikurangi oceanic plateaus southwestern Pacific Ocean, inferred have formed a single plateau called Java Nui. Sedimentary osmium (Os) isotopic compositions one best p...
Ornithomimosaurs (ostrich-mimic dinosaurs) are a common element of some Cretaceous dinosaur assemblages of Asia and North America. Here, we describe a new species of ornithomimosaur, Beishanlong grandis, from an associated, partial postcranial skeleton from the Aptian-Albian Xinminpu Group of northern Gansu, China. Beishanlong is similar to another Aptian-Albian ornithomimosaur, Harpymimus, wit...
Brachiopod faunas from the Aptian- Cenomanian Vezk section in southwesternIran comprise ten species in six genera, namely Sellithyris cenomanensis, Sellithyris tornacensis, Sellithyris phaseolina, Phaseolina phaseolina, Tropeothyris sp., Concinnithyris subundata, Kingena arenosa, Cyclothyris difformis, Cyclothyris sp. and Cyclothyris compressa. All species are recorded for the first time from t...
The organic carbon isotope (δ13Corg) curve for ~1.7-km-thick mid-Cretaceous strata of the Chaqiela section in Gamba area, southern Tibet is presented in this study. C-isotopic chemostratigraphic correlation combined with biostratigraphic constraints show that the Chaqiela section spans early Aptian through early Campanian period, and that almost all of the carbon cycle perturbations and Oceanic...
Abstract Reconstruction of Aptian–Albian paleoclimate obtained from marine records remains a challenging topic, but studies on coeval terrestrial and trigger mechanisms have lagged substantially. In this study, new multiproxy data mudrocks in the Fuxin Basin NE China provide high-resolution climate record East Asia. Here, we demonstrate occurrence cooling during late Aptian (118–113 Ma), which ...
[1] Mid-Cretaceous (Barremian-Turonian) plankton preserved in deep-sea marl, organic-rich shale, and pelagic carbonate hold an important record of how the marine biosphere responded to shortand long-term changes in the ocean-climate system. Oceanic anoxic events (OAEs) were short-lived episodes of organic carbon burial that are distinguished by their widespread distribution as discrete beds of ...
Cretaceous planktonic foraminifers from Ocean Drilling Program (ODP) Leg 130 consist of two age groups: one dominantly Aptian in age and the other dominantly Maastrichtian. The oldest dated sediments from Ontong Java Plateau occur at ODP Site 807 and are assigned to the early Aptian Globigerinelloides blowi Zone. The assemblage correlates closely with Aptian foraminifers from Deep Sea Drilling ...
The echinoid fauna of Basab area (Aptian), northwest of Kerman, is fairly rich and diverse, represented by Pygaulidae, Acropeltidae, Emiratiidae, Toxasteridae, Holectypidae, Stomechinidae and Saleniidae. Four regular echinoid species, among which three are new, assigned to genus Tetragramma Agassiz, are described and illustrated in the present paper. The new species are Tetragramma basabensis, ...
BACKGROUND Pterosaurs have been known from the Cretaceous sediments of the Isle of Wight (southern England, United Kingdom) since 1870. We describe the three-dimensional pelvic girdle and associated vertebrae of a small near-adult pterodactyloid from the Atherfield Clay Formation (lower Aptian, Lower Cretaceous). Despite acknowledged variation in the pterosaur pelvis, previous studies have not ...
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