Eocene ostracodes from Hahajima Island of the Ogasawara (Bonin) Islands, northwestern Pacific, and their paleobiogeographic significance in the West Pacific

2009 ◽  
Vol 83 (2) ◽  
pp. 219-237 ◽  
Author(s):  
Tatsuhiko Yamaguchi ◽  
Takahiro Kamiya
Keyword(s):  
New Species ◽  
Late Eocene ◽  
Northwestern Pacific ◽  
The West ◽  
Bonin Islands ◽  
Center Of Origin ◽  
West Pacific ◽  
The North ◽  
The Pacific ◽  
Mariana Arc

During the Eocene, Hahajima Island of the Ogasawara (Bonin) Islands of the Izu-Mariana Arc in the North Pacific was located near the present-day position of western Pacific Micronesia. We identified 17 Eocene ostracode species from the island, of which are new species and likely endemic to this island or to the West Pacific. These new species are systematically described herein and include: Costa matsumarui n. sp., Cytherelloidea ogasawaraensis n. sp., Havanardia ujiiei n. sp., Jugosocythereis nishii n. sp., Neonesidea boninensis n. sp., Schizocythere antiquimicronesiana n. sp., and Uroleberis hahajimaensis n. sp. The Eocene ostracode fauna has a higher rate of endemism than does the modern Micronesian fauna and contains Tethyan genera. These findings contradict a hypothesis that the Pacific fauna had a higher endemism rate after the Paleogene. The findings support another hypothesis that some genera invaded the Pacific from Tethys during the Paleogene. They suggest that West Pacific species did not disperse to the periphery of the Indo-West Pacific region during the Middle–Late Eocene. The “center of origin” hypothesis cannot be applied to Middle–Late Eocene marine ostracode biogeography.

scholarly journals Phylogeny and Biogeography of Branchipolynoe (Polynoidae, Phyllodocida, Aciculata, Annelida), with Descriptions of Five New Species from Methane Seeps and Hydrothermal Vents

Diversity ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 153 ◽  
Author(s):  
Johanna Lindgren ◽  
Avery S. Hatch ◽  
Stephané Hourdez ◽  
Charlotte A. Seid ◽  
Greg W. Rouse
Keyword(s):  
New Species ◽  
Papua New Guinea ◽  
Hydrothermal Vents ◽  
Costa Rican ◽  
Methane Seeps ◽  
The West ◽  
West Pacific ◽  
Mitochondrial Coi ◽  
The North ◽  
Nuclear Its

The four named species of Branchipolynoe all live symbiotically in mytilid mussels (Bathymodiolus) that occur at hydrothermal vents or methane seeps. Analyses using mitochondrial (COI and 16S) and nuclear (ITS) genes, as well as morphology, were conducted on a collection of Branchipolynoe from Pacific Costa Rican methane seeps and West Pacific hydrothermal vents. This revealed five new species of Branchipolynoe, and these are formally described. The new species from Costa Rica live in three species of Bathymodiolus mussels (also new) at depths ranging from 1000 to 1800 m. Branchipolynoe kajsae n. sp. and Branchipolynoe halliseyae n. sp. were found in all three undescribed Bathymodiolus species, while Branchipolynoe eliseae n. sp. was found in Bathymodiolus spp. 1 and 2, and Branchipolynoe meridae n. sp. was found in Bathymodiolus spp. 1 and 3. Hence, Bathymodiolus sp. 1 hosted all four of the new species, while the other two Bathymodiolus hosted three each. Most mussels contained only one specimen of Branchipolynoe; where there was more than one, these were often a female and smaller male of the same species. The newly discovered species from the West Pacific, Branchipolynoe tjiasmantoi n. sp., lives in unidentified Bathymodiolus at depths ranging from 674 to 2657 m from hydrothermal vents in the North Fiji (Fiji) and Lau Basins (Tonga) and also from New Zealand, Vanuatu, and the Manus Basin (Papua New Guinea). The phylogenetic and biogeographical implications of this diversity of Branchipolynoe are discussed.

Geographical restriction as a guide to the causes of extinction: the case of the cold northern oceans during the Neogene

Paleobiology ◽  
1989 ◽  
Vol 15 (4) ◽  
pp. 335-356 ◽  
Author(s):  
Geerat J. Vermeij
Keyword(s):  
Primary Productivity ◽  
North Pacific ◽  
Early Pleistocene ◽  
Northwestern Pacific ◽  
Supporting Evidence ◽  
Geographical Patterns ◽  
The North ◽  
The Pacific ◽  
Late Neogene ◽  
The North Pacific

Geographical restriction to refuges implies the regional extinction of taxa in areas of the previous range falling outside the refuge. A comparison of the circumstances in the refuge with those in areas from which the taxa were eliminated is potentially informative for pinpointing the causes of extinction. A synthesis of data on the geographical and stratigraphical distributions of cool-water molluscs of the North Pacific and North Atlantic Oceans during the late Neogene reveals four patterns of geographical restriction, at least two of which imply that climatic cooling was not the only cause of extinction during the last several million years. These four patterns are (1) the northwestern Pacific restriction, involving 15 taxa whose amphi-Pacific distributions during the late Neogene became subsequently restricted to the Asian side of the Pacific; (2) the northwestern Atlantic restriction, involving six taxa whose early Pleistocene distribution is inferred to have been amphi-Atlantic, but whose present-day and late Pleistocene ranges are confined to the northwestern Atlantic; (3) a vicariant Pacific pattern, in which many ancestral amphi-Pacific taxa gave rise to separate eastern and western descendants; and (4) the circumboreal restriction, involving six taxa whose early Pleistocene distribution, encompassing both the Atlantic and Pacific Oceans, became subsequently limited to the North Pacific. Like the Pliocene extinctions in the Atlantic, previously studied by Stanley and others, the vicariant Pacific pattern is most reasonably interpreted as having resulted from regional extinction of northern populations in response to cooling. The northwestern Pacific and Atlantic restrictions, however, cannot be accounted for in this way. In contrast to the northeastern margins of the Pacific and Atlantic, the northwestern margins are today characterized by wide temperature fluctuations and by extensive development of shore ice in winter. Northeastern, rather than northwestern, restriction would be expected if cooling were the overriding cause of regional extinction. Among the other possible causes of extinction, only a decrease in primary productivity can account for the observed northwestern and circumboreal patterns of restriction. Geographical patterns of body size and the distribution of siliceous deposits provide supporting evidence that primary productivity declined after the Miocene in the northeastern Pacific, but remained high in the northwestern Pacific, and that productivity in the Pacific is generally higher than it is in the Atlantic. The patterns of geographical restriction in the northern oceans thus provide additional support to previous inferences that reductions in primary productivity have played a significant role in marine extinctions.

A review of the genus Platyrhina (Chondrichthys: Platyrhinidae) from the northwestern Pacific, with descriptions of two new species

Zootaxa ◽  
2011 ◽  
Vol 2738 (1) ◽  
pp. 26 ◽  
Author(s):  
YUKIO IWATSUKI ◽  
KEI MIYAMOTO ◽  
KAZUHIRO NAKAYA ◽  
JIE ZHANG
Keyword(s):  
New Species ◽  
Pacific Coast ◽  
Northwestern Pacific ◽  
Nominal Species ◽  
Undescribed Species ◽  
White Pigment ◽  
Light Yellow ◽  
The Pacific ◽  
Two New Species ◽  
Pacific Species

The genus Platyrhina from the northwestern Pacific was reviewed, including a redescription and neotype proposal for Platyrhina sinensis (Bloch and Schneider 1801), and the description of two new species. Platyrhina limboonkengi Tang 1933 is relegated to the synonymy of P. sinensis, both species having two rows of hooked thorns on the mid-dorsum of the tail. Specimens previously widely identified as P. sinensis, but characterized by one row of such hooked thorns, represented an undescribed species, herein named Platyrhina tangi Iwatsuki, Zhang and Nakaya sp. nov. Platyrhina hyugaensis Iwatsuki, Miyamoto and Nakaya sp. nov., known from specimens limited primarily to the Hyuga Nada Sea, off Miyazaki, the Pacific coast of southern Japan, is similar to P. tangi in having one row of hooked thorns on the mid-dorsum of the trunk and tail, but differs in having larger hooked thorns, not encircled by light yellow or white pigment on the orbital, nape and scapular regions, and a pair of hooked thorns (absent in P. tangi) anteriorly on the scapular region. Nominal species are discussed and key to northwestern Pacific species of Platyrhina is provided.

On a new species of Siboglinum (Pogonophora), found on both sides of the North Atlantic

1963 ◽  
Vol 43 (2) ◽  
pp. 513-517 ◽  
Author(s):  
Eve C. Southward
Keyword(s):  
New Species ◽  
Shallow Water ◽  
North Atlantic ◽  
Related Species ◽  
The North ◽  
The Pacific ◽  
The North Atlantic ◽  
A New Species

A description is given of Siboglinum holmei sp.nov., a shallow-water Atlantic species. It is compared with S. caulleryi, a related species from the Pacific.

Deep-sea chitons from sunken wood in the West Pacific (Mollusca: Polyplacophora: Lepidopleurida): taxonomy, distribution, and seven new species

Zootaxa ◽  
2012 ◽  
Vol 3195 (1) ◽  
pp. 1 ◽  
Author(s):  
JULIA D. SIGWART ◽  
BORIS I. SIRENKO
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Solomon Islands ◽  
The Philippines ◽  
Identification Key ◽  
Sensory Function ◽  
The West ◽  
West Pacific ◽  
Important Habitat

Natural deposits of sunken wood provide an important habitat for deep-sea invertebrates. Deep-sea chitons in the primitiveorder Lepidopleurida are typically collected rarely and as single specimens. However, these animals have been recoveredin large densities associated with sunken wood in the tropical West Pacific, in groups of up to 50 individuals. Four deep-sea expeditions in the West Pacific, to the Philippines, Solomon Islands, and Vanuatu, recovered a large number of poly-placophorans. We have examined the morphology as well as the range and distribution of these species, based on the larg-est collection ever examined (more than 1300 individuals). These species show potentially adapted characters associatedwith exploitation of sunken wood as habitat, such as protruding caps on sensory shell pores (aesthetes) and large interseg-mental bristles with potential sensory function. In this study we investigated the twenty-two species recovered, includingseven newly described here (Leptochiton consimilis n. sp., L. angustidens n. sp., L. dykei n. sp., L. samadiae n. sp., L.longisetosus n. sp., L. clarki n. sp., L. schwabei n. sp.), and provide the first identification key to the 34 lepidopleuran chitons known from sunken wood worldwide.

Peniculus asinus (Copepoda: Pennellidae), a new species of copepod parasitic on fishes of the genus Sebastes along the west coast of North America

1977 ◽  
Vol 55 (12) ◽  
pp. 1988-1991 ◽  
Author(s):  
Z. Kabata ◽  
S. N. Wilkes
Keyword(s):  
New Species ◽  
North America ◽  
West Coast ◽  
Pacific Coast ◽  
The West ◽  
Unique Member ◽  
The Pacific ◽  
The Family ◽  
A New Species

Peniculus asinus, a new species of copepod parasitic on Sebastes (Pisces: Teleostei) off the Pacific coast of Canada is described and illustrated. The copepod is an unique member of its genus in that it possesses cephalothoracic holdfast processes. The discovery of a Peniculus with these processes is taken as evidence confirming the place of this genus in the family Pennellidae.

Definition of the Genus Grammonota (Araneae: Erigonidae), with Descriptions of Seven New Species

1959 ◽  
Vol 91 (4) ◽  
pp. 232-242 ◽  
Author(s):  
C. D. Dondale
Keyword(s):  
Rocky Mountains ◽  
West Indies ◽  
Pacific Coast ◽  
James Bay ◽  
The West ◽  
The North ◽  
The Pacific ◽  
Gulf States ◽  
The Many ◽  
Definition Of

Grammonota Emerton, 1882, is one of the many uniform genera that constitute the large and complex family Erigonidae. All of the 28 species and one subspecies recognized by the present writer are American in range, and representatives occur from southwestern Alaska and James Bay in the north to Central America and the West Indies. A few species are arctic-alpine, or are restricted to the Pacific coast, but most occur east of the Rocky Mountains from southern Canada to the Gulf States.

North Pacific Subtropical Mode Water Controlled by the Atlantic Multi-Decadal Variability

2020 ◽  
Author(s):  
Baolan wu ◽  
Xiaopei lin ◽  
Lisan yu
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Decadal Variability ◽  
Heat Content ◽  
Northwestern Pacific ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
Mean Temperature ◽  
The Pacific

<p><strong>The North Pacific Subtropical Mode Water (mode water hereafter) is a vertically homogeneous thermocline water mass, occupying the entire subtropical Western Pacific Ocean. By transporting mass, heat and nutrients from the surface into the subsurface ocean, it provides memory of climate variability and is a potential source of predictability. Previous studies attributed decadal variability of the mode water mean temperature to the Pacific Decadal Oscillation (PDO). Using available observations and reanalysis data, here we show that decadal to multi-decadal variability of the mode water mean temperature is controlled by the Atlantic Multi-Decadal Variability (AMV) instead. During an AMV positive phase, warm sea surface temperatures (SSTs) in the north Atlantic Ocean weaken the subtropical North</strong> <strong>Pacific westerlies, and the anomalous easterlies in the subtropical west Pacific drive an anomalous northward Ekman transport of warm water into the mode water formation area. </strong><strong>This increases the mode water temperature through subduction</strong><strong>, driving variability of the upper-layer ocean heat content and fish catches in the Northwestern Pacific. This mechanism is supported by a long pre-industrial model simulation with multiple AMV cycles and by a Pacemaker model experiment, in which the AMV forcing alone is shown to drive the variability of the mode water. Our finding suggests that the AMV is an important driver for decadal climate and ecosystem variability and provides memory for prediction in the Pacific Ocean.</strong></p>

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