نتایج جستجو برای: middle cretaceous

تعداد نتایج: 163403  

2014
Ellen Thomas

Deep-sea benthic foraminifera live in the largest habitat on Earth, constitute an important part of its benthic biomass, and form diverse assemblages with common cosmopolitan species. Modern deep-sea benthic foraminiferal assemblages are strongly infl uenced by events affecting their main food source, phytoplankton (a relationship known as bentho-pelagic coupling). Surprisingly, benthic foramin...

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Diabases, pillow lavas and basaltic flows in the Nain-Dehshir ophiolites are marked with flat to slightly depleted pattern in REE chondrite-normalized diagram and are characterized by depletion in HFSE and enrichment in LILE. This geochemical behavior can be considered for lavas erupted in arc-related environments. Clinopyroxene in these rocks shows low content of TiO2 and resemble those found ...

ژورنال: اقیانوس شناسی 2020

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...

ژورنال: اقیانوس شناسی 2021

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...

Journal: :The New phytologist 2008
P Wilf

Plants and herbivorous insects have dominated terrestrial ecosystems for over 300 million years. Uniquely in the fossil record, foliage with well-preserved insect damage offers abundant and diverse information both about producers and about ecological and sometimes taxonomic groups of consumers. These data are ideally suited to investigate food web response to environmental perturbations, and t...

2014
Pablo A. Gallina Sebastián Apesteguía Alejandro Haluza Juan I. Canale

Diplodocids are by far the most emblematic sauropod dinosaurs. They are part of Diplodocoidea, a vast clade whose other members are well-known from Jurassic and Cretaceous strata in Africa, Europe, North and South America. However, Diplodocids were never certainly recognized from the Cretaceous or in any other southern land mass besides Africa. Here we report a new sauropod, Leikupal laticauda ...

2017
J Krishna

It updates the biostratigraphic refinement in the Indian Mesozoics with focus on the Triassic in Spiti, Jurassic in Kachchh, and Cretaceous in Kachchh and Cauvery. As an example, the ammonoid stratigraphic zonation in Kachchh basin inclusive of the new Oxfordian zones, as also the origin of the basin are developed at length. Also are touched upon the salient pre-sequence Paleozoic features as b...

2009
Dirk Fuchs Robert Weis

The fossil record of cuttlefish, squid and octopus has received relatively little attention. Among malacologists, the opinion is widespread that these mainly softbodied coleoids have a poor fossil record. However, thanks to Konservat-Lagerst tten such as the Early Jurassic Posidonian Shales of Holzmaden (Germany), the Middle Jurassic La-Voulte-sur-Rh ne (France) and the Late Jurassic Limestones...

Journal: :Proceedings. Biological sciences 2012
Diego Pol Oliver W M Rauhut

Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is...

Journal: :Current Biology 2012
Tai-ping Gao Chung-kun Shih Xing Xu Shuo Wang Dong Ren

Parasite-host associations among insects and mammals or birds are well attended by neontological studies [1]. An Eocene bird louse compression fossil [2, 3] and several flea specimens from Eocene and Oligocene ambers [4-8], reported to date, are exceptionally similar to living louse and flea taxa. But the origin, morphology, and early evolution of parasites and their associations with hosts are...

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