scholarly journals Late Quaternary deep-sea ostracod taxonomy of the eastern North Atlantic Ocean

2015 ◽  
Vol 34 (1) ◽  
pp. 21-49 ◽  
Author(s):  
Moriaki Yasuhara ◽  
Hisayo Okahashi
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
North Atlantic Ocean ◽  
Late Quaternary ◽  
Taxonomic Revision ◽  
Quaternary Sediments ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Eastern North Atlantic ◽  
Microscopy Images

Abstract. Taxonomic revision and re-evaluation of the eastern North Atlantic deep-sea ostracods are conducted based on late Quaternary sediments from Ocean Drilling Program (ODP) Hole 982A, Rockall Plateau, eastern North Atlantic. Twenty-one genera and 51 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images. Six new species are described: Polycope lunaris, Argilloecia labri, Bythoceratina nuda, Cytheropteron colesoabyssorum, Cytheropteron colesopunctatum and Cytheropteron paramediotumidum. Excellent fossil ostracod preservation in this sediment core enabled us to provide a robust taxonomic baseline of the eastern North Atlantic deep-sea ostracods for application to palaeoceanographical, palaeoecological and biogeographical studies.

Quaternary deep-sea ostracode taxonomy of Ocean Drilling Program Site 980, eastern North Atlantic Ocean

2014 ◽  
Vol 88 (4) ◽  
pp. 770-785 ◽  
Author(s):  
Moriaki Yasuhara ◽  
Hisayo Okahashi
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
North Atlantic Ocean ◽  
Late Quaternary ◽  
Eastern Slope ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Eastern North Atlantic ◽  
One New Species ◽  
Microscopy Images

Ocean Drilling Program (ODP) Holes 980 B and C, Feni Drift at the eastern slope of the Rockall Plateau, eastern North Atlantic, were examined for late Quaternary deep-sea ostracode taxonomy. Nineteen genera and 32 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images. One new speciesCytheropteron paramassonin. sp. is described and one new nameEucytherura zehaliis proposed forEucytherura hazeliYasuhara et al., 2009. This study provides updated taxonomic information for deep-sea ostracode genera and species from the eastern North Atlantic, which is an important baseline for application of deep-sea ostracodes to paleoceanographical reconstructions and paleoecological studies in this region.

scholarly journals The deep-sea pennatulacean genus Porcupinella – with the description of a new species from Tasmania (Anthozoa, Octocorallia, Chunellidae)

ZooKeys ◽  
2021 ◽  
Vol 1019 ◽  
pp. 1-14
Author(s):  
Gary C. Williams
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Deep Sea ◽  
Type Species ◽  
Growth Form ◽  
North Atlantic Ocean ◽  
Comparative Morphology ◽  
Tasman Sea ◽  
Eastern North Atlantic ◽  
A New Species

The recently described deep-sea pennatulacean genus Porcupinella was previously known only by the type species, Porcupinella profunda from the equatorial eastern Atlantic to the eastern North Atlantic Ocean. New data is provided on morphology, distribution, bathymetry, and related taxa. A second species is added here as well – a new species is described from the Tasman Sea in the southwestern Pacific. The new species, Porcupinella tasmanica, is distinguished from P. profunda by its distinctive hook-shaped growth form, laterally compressed dorsal keel, and differing regions that are occupied by siphonozooids. A key to the species of the deep-sea pennatulacean family Chunellidae is included based on comparative morphology.

scholarly journals Variations in Mediterranean–Atlantic exchange across the late Pliocene climate transition

2018 ◽  
Vol 14 (3) ◽  
pp. 339-350
Author(s):  
Ángela García-Gallardo ◽  
Patrick Grunert ◽  
Werner E. Piller
Keyword(s):  
North Atlantic ◽  
Saline Water ◽  
Late Quaternary ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Time Interval ◽  
Strait Of Gibraltar ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
The Mediterranean

Abstract. Mediterranean–Atlantic exchange through the Strait of Gibraltar plays a significant role in the global ocean–climate dynamics in two ways. On one side, the injection of the saline and warm Mediterranean Outflow Water (MOW) contributes to North Atlantic deep-water formation. In return, the Atlantic inflow is considered a sink of less saline water for the North Atlantic Ocean. However, while the history of MOW is the focus of numerous studies, the Pliocene Atlantic inflow has received little attention so far. The present study provides an assessment of the Mediterranean–Atlantic exchange with a focus on the Atlantic inflow strength and its response to regional and global climate from 3.33 to 2.60 Ma. This time interval comprises the mid-Pliocene warm period (MPWP; 3.29–2.97 Ma) and the onset of the Northern Hemisphere glaciation (NHG). For this purpose, gradients in surface δ18O records of the planktonic foraminifer Globigerinoides ruber between the Integrated Ocean Drilling Program (IODP) Hole U1389E (Gulf of Cádiz) and Ocean Drilling Program (ODP) Hole 978A (Alboran Sea) have been evaluated. Interglacial stages and warm glacials of the MPWP revealed steep and reversed (relative to the present) W–E δ18O gradients suggesting a weakening of Mediterranean–Atlantic exchange likely caused by high levels of relative humidity in the Mediterranean region. In contrast, periods of stronger inflow are indicated by flat δ18O gradients due to more intense arid conditions during the severe glacial Marine Isotope Stage (MIS) M2 and the initiation of NHG (MIS G22, G14, G6–104). Intensified Mediterranean–Atlantic exchange in cold periods is linked to the occurrence of ice-rafted debris (IRD) at low latitudes and a weakening of the Atlantic Meridional Overturning Circulation (AMOC). Our results thus suggest the development of a negative feedback between AMOC and exchange rates at the Strait of Gibraltar in the latest Pliocene as it has been proposed for the late Quaternary.

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