scholarly journals Taxonomic diversity dynamics of early cretaceous brachiopods and gastropods in the Azerbaijanian domains of the Lesser Caucasus (Neo-Tethys Ocean)

2014 ◽  
pp. 17-31 ◽  
Author(s):  
Dmitry Ruban
Keyword(s):  
Early Cretaceous ◽  
Benthic Invertebrates ◽  
Taxonomic Diversity ◽  
Northern Caucasus ◽  
Tectonic Zones ◽  
Tethys Ocean ◽  
Lesser Caucasus ◽  
A Minor ◽  
Marine Benthic Invertebrates ◽  
Diversity Dynamics

Palaeontological data available from the Azerbaijanian domains (Somkhit-Agdam, Sevan-Karabakh, and Miskhan-Kafan tectonic zones) of the Lesser Caucasus permit reconstruction of the regional taxonomic diversity dynamics of two groups of Early Cretaceous marine benthic invertebrates. Stratigraphical ranges of 31 species and 14 genera of brachiopods and 40 species and 31 genera of gastropods are considered. The total number of species and genera of brachiopods was low in the Berriasian-Valanginian and then rose to peak in the Barremian. Then, the diversity declined in the Aptian, and brachiopods are not known regionally from the Albian. Gastropods appeared in the Hauterivian and experienced a strong radiation in the Barremian. The diversity of species and genera declined in the Aptian (with a minor radiation in the Middle Aptian), and no gastropods are reported from the Albian. Globally, the number of brachiopod genera remained stable through the Early Cretaceous, and the number of gastropod genera increased stepwise with the maximum in the Albian. The regional and global patterns of the diversity dynamics differed for the both groups of marine benthic invertebrates. The Barremian maximum of the taxonomic diversity coincided with the regional flourishing of reefal ecosystems. The taxonomic diversity dynamics of brachiopods in the Azerbaijanian domains of the Lesser Caucasus is very similar to those of the Northern Caucasus, which is an evidence of proximity of these regions during the Early Cretaceous.

Dispersal of marine benthic invertebrates through ice rafting

Ecology ◽  
2013 ◽  
Vol 94 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Colin B. A. Macfarlane ◽  
David Drolet ◽  
Myriam A. Barbeau ◽  
Diana J. Hamilton ◽  
Jeff Ollerhead
Keyword(s):  
Benthic Invertebrates ◽  
Ice Rafting ◽  
Marine Benthic Invertebrates

The Distribution of Hyas Araneus (L.) and Hyas Coarctatus Leach (Crustacea: Decapoda: Brachyura) in the North Sea and the Svalbard Region

1985 ◽  
Vol 65 (1) ◽  
pp. 195-201 ◽  
Author(s):  
M. F. Dyer
Keyword(s):  
Relative Density ◽  
North Sea ◽  
Benthic Invertebrates ◽  
Distribution Patterns ◽  
The North ◽  
The North Sea ◽  
Hyas Araneus ◽  
Presence And Absence ◽  
Marine Benthic Invertebrates

The distribution patterns of many marine benthic invertebrates are not well known, and when records exist they are usually in the form of presence and absence data with little or no information on the relative density of populations from area to area.

scholarly journals Bacteria Associated with Marine Benthic Invertebrates from Polar Environments: Unexplored Frontiers for Biodiscovery?

Diversity ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 80 ◽  
Author(s):  
Angelina Lo Giudice ◽  
Carmen Rizzo
Keyword(s):  
Benthic Invertebrates ◽  
Marine Invertebrates ◽  
Biologically Active ◽  
The Arctic ◽  
Physiological Changes ◽  
Invertebrate Host ◽  
Cold Adapted ◽  
Marine Areas ◽  
Marine Benthic Invertebrates ◽  
Symbiotic Community

The ecological function of bacteria-invertebrate interactions in Polar areas remains poorly understood, despite increasing evidence that microbial metabolites may play pivotal roles in host-associated chemical defense and in shaping the symbiotic community structure. The metabolic and physiological changes that these organisms undergo in response to adapting to extreme conditions result in the production of structurally and functionally novel biologically active molecules. Deepening our knowledge on the interactions between bacteria and their invertebrate host would be highly helpful in providing the rationale for why (e.g., competition or cooperative purpose) and which (whether secondary metabolites, enzymes, or proteins) bioactive compounds are produced. To date, cold-adapted bacteria associated with marine invertebrates from the Arctic and Antarctica have not been given the attention they deserve and the versatility of their natural products remains virtually unexplored, even if they could represent a new attractive frontier in the search for novel natural compounds. This review is aimed at showcasing the diversity of cold-adapted bacteria associated with benthic invertebrates from Polar marine areas, highlighting the yet unexplored treasure they represent for biodiscovery.

Early Cretaceous trigoniids of the Northern Caucasus

2017 ◽  
Vol 51 (9) ◽  
pp. 899-972
Author(s):  
B. T. Yanin ◽  
T. N. Bogdanova
Keyword(s):  
Early Cretaceous ◽  
Northern Caucasus

Biotic changes linked to a minor anoxic event (Faraoni Level, latest Hauterivian, Early Cretaceous)

2005 ◽  
Vol 224 (1-3) ◽  
pp. 186-199 ◽  
Author(s):  
Miguel Company ◽  
Roque Aguado ◽  
José Sandoval ◽  
José M. Tavera ◽  
Concepción Jiménez de Cisneros ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Anoxic Event ◽  
A Minor

The Early Cretaceous San Juan Plutonic Suite, Ecuador: a magma chamber in an oceanic plateau?

2004 ◽  
Vol 41 (10) ◽  
pp. 1237-1258 ◽  
Author(s):  
Marc Mamberti ◽  
Henriette Lapierre ◽  
Delphine Bosch ◽  
Etienne Jaillard ◽  
Jean Hernandez ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Minor Component ◽  
San Juan ◽  
Type I ◽  
Oceanic Plateau ◽  
Depleted Mantle ◽  
Plutonic Rocks ◽  
Ultramafic Cumulates ◽  
A Minor ◽  
End Members

Sections through an oceanic plateau are preserved in tectonic slices in the Western Cordillera of Ecuador (South America). The San Juan section is a sequence of mafic–ultramafic cumulates. To establish that these plutonic rocks formed in an oceanic plateau setting, we have developed criteria that discriminate intrusions of oceanic plateaus from those of other tectonic settings. The mineralogy and crystallization sequence of the cumulates are similar to those of intra-plate magmas. Clinopyroxene predominates throughout, and orthopyroxene is only a minor component. Rocks of intermediate composition are absent, and hornblende is restricted to the uppermost massive gabbros within the sequence. The ultramafic cumulates are very depleted in light rare-earth elements (LREE), whereas the gabbros have flat or slightly enriched LREE patterns. The composition of the basaltic liquid in equilibrium with the peridotite, calculated using olivine compositions and REE contents of clinopyroxene, contains between 16% and 8% MgO and has a flat REE pattern. This melt is geochemically similar to other accreted oceanic plateau basalts, isotropic gabbros, and differentiated sills in western Ecuador. The Ecuadorian intrusive and extrusive rocks have a narrow range of εNdi (+8 to +5) and have a rather large range of Pb isotopic ratios. Pb isotope systematics of the San Juan plutonic rocks and mineral separates lie along a mixing line between the depleted mantle (DMM) and the enriched-plume end members. This suggests that the Ecuadorian plutonic rocks generated from the mixing of two mantle sources, a depleted mid-oceanic ridge basalt (MORB) source and an enriched one. The latter is characterized by high (207Pb/204Pb)i ratios and could reflect a contamination by recycled either lower continental crust or oceanic pelagic sediments and (or) altered oceanic crust (enriched mantle type I, EMI). These data suggest that the San Juan sequence represents the plutonic components of an Early Cretaceous oceanic plateau, which accreted in the Late Cretaceous to the Ecuadorian margin.

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