نتایج جستجو برای: barremian aptian

تعداد نتایج: 602  

Journal: Geopersia 2011
Abbas Ghaderi Ali asghar Aryaei Alireza Ashouri Morteza Taherpour Khalilabad

A stratigraphic section from the Tirgan Formation was selected in Arkan village nearby Bojnourd city in order to study echinoderm fauna systematically. Many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. Microscopie slides were also prepared and studied. All slides contain benthic foraminifers and c...

2003
STUART A. ROBINSON STEPHEN P. HESSELBO

Fossil-wood carbon-isotope data are presented for the Wessex Formation, a non-marine unit within the Lower Cretaceous (Valanginian–Barremian) Wealden Group of the Isle of Wight and Dorset, southern England. The carbon-isotope values have a range ( C c. 26.6 to 19.8‰) that is consistent with that expected for Mesozoic C3 plants. Consideration of the Isle of Wight fossil-wood carbon-isotope data ...

Journal: :Proceedings. Biological sciences 2010
Daqing Li Mark A Norell Ke-Qin Gao Nathan D Smith Peter J Makovicky

The fossil record of tyrannosauroid theropods is marked by a substantial temporal and morphological gap between small-bodied, Barremian taxa, and extremely large-bodied taxa from the latest Cretaceous. Here we describe a new tyrannosauroid, Xiongguanlong baimoensis n. gen. et sp., from the Aptian-Albian Xinminpu Group of western China that represents a phylogenetic, morphological, and temporal ...

Journal: :Acta Palaeobotanica 2022

Palynostratigraphic and palynofacies analysis have been performed on hydrocarbon seep carbonate, carbonate nodule mudstone samples from the Early Cretaceous Kuhnpasset Beds in area of Wollaston Forland, Northeast Greenland. Three informal palynostratigraphic zones defined based dinoflagellate cyst occurrences. The range ?early Barremian to early Aptian age, correlate with previously These indic...

Journal: :Cretaceous Research 2021

Internal moulds of rudist bivalves from the basal Exu Formation western Araripe Basin, northeastern Brazil, are identified as Early Cretaceous (Barremian to Aptian) radiolitidin caprinuloideid genus cf. Amphitriscoelus Harris and Hodson. The rudists occur part a sparse assemblage remané fossils in Formation, fluvial sandstone resting disconformably on Santana Group likely have been derived shal...

2002
R. Mark Leckie Timothy J. Bralower Richard Cashman

[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 ...

2013
Darren Naish Martin Simpson Gareth Dyke

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 ...

Journal: :The depositional record 2022

Shifting palaeoceanographic and palaeoclimatic conditions together with fluctuating eustatic sea levels during the Early Cretaceous Aptian stage led to a globally widespread deposition of organic-rich marine sediments designated Oceanic Anoxic Event 1a. Here detailed lithostratigraphic geochemical study is presented for 35.6 m Cabó Formation, part Organyà Basin, North-east Spain, assess intermi...

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