scholarly journals Scaldiporia vandokkumi, a new pontoporiid (Mammalia, Cetacea, Odontoceti) from the Late Miocene to earliest Pliocene of the Westerschelde estuary (The Netherlands)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3991 ◽  
Author(s):  
Klaas Post ◽  
Stephen Louwye ◽  
Olivier Lambert
Keyword(s):  
The Netherlands ◽  
North Atlantic ◽  
Late Miocene ◽  
New Genus ◽  
South Atlantic ◽  
New Genus And Species ◽  
The North ◽  
Westerschelde Estuary ◽  
The Family ◽  
The North Atlantic

Background The family Pontoporiidae (Cetacea, Odontoceti, Inioidea) is currently represented in our oceans by just one species of diminutive dolphin (Pontoporia blainvillei, franciscana). Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information. Methods Based on an almost complete fossil cranium of pontoporiid from the Westerschelde estuary, The Netherlands, whose preservation allows for detailed morphological observations, we describe a new genus and species. The latter is compared to other pontoporiids, as well as a few non-pontoporiid inioids. A phylogenetic analysis is performed to investigate the relationship of S. vandokkumi with the best-known extinct and extant inioids. Palynological analysis of the sediment associated to the holotype is used to assess its geological age. Results and discussion The new genus and species Scaldiporia vandokkumi is characterized among others by greatly thickened premaxillary eminences reaching the level of the antorbital notch. Palynologically dated from the late Tortonian—earliest Zanclean (7.6–5 Ma, Late Miocene—earliest Pliocene), this new pontoporiid confirms the surprising past diversity of marine inioids in the North Atlantic area. Finally the content of the pontoporiid subfamily Brachydelphininae is briefly discussed.

scholarly journals A new species of rorqual whale (Cetacea, Mysticeti, Balaenopteridae) from the Late Miocene of the Southern North Sea Basin and the role of the North Atlantic in the paleobiogeography of Archaebalaenoptera

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8315 ◽  
Author(s):  
Michelangelo Bisconti ◽  
Dirk K. Munsterman ◽  
René H.B. Fraaije ◽  
Mark E.J. Bosselaers ◽  
Klaas Post
Keyword(s):  
New Species ◽  
The Netherlands ◽  
North Sea ◽  
North Atlantic ◽  
Late Miocene ◽  
North Atlantic Ocean ◽  
Center Of Origin ◽  
Southern North Sea ◽  
The North ◽  
The North Atlantic

Background The rich fossil record of rorqual and humpback whales (Cetacea, Mysticeti, Balaenopteridae) is mainly characterized by monotypic genera since genera including more than one species are extremely rare. The discovery of new species belonging to known genera would be of great importance in order to better understand ancestor-descendant relationships and paleobiogeographic patterns in this diverse group. Recent discoveries in the southern North Sea Basin yielded a number of reasonably well preserved fossil balaenopterids from the Late Miocene; this sample includes a balaenopterid skull from Liessel, The Netherlands, which shares key characters with Archaebalaenoptera castriarquati from the Pliocene of Mediterranean. This skull is permanently held by Oertijdmuseum, Boxtel, The Netherlands, with the number MAB002286 and is investigated here. Methods A detailed comparative anatomical analysis of the skull MAB002286 is performed in order to understand its relationships. The age of the skull is determined by dinocyst analysis of the associated sediment. A paleobiogeographic analysis is performed to understand paleobiogeographic patterns within the balaenopterid clade the new skull belongs to. Results Our work resulted in the description of Archaebalaenoptera liesselensis new species. The geological age of the holotype skull is between 8.1 and 7.5 Ma. The phylogenetic relationships of this species reveals that it is monophyletic with Archaebalaenoptera castriarquati from the Italian Pliocene. Moreover, in combination with a more basal species of Archaebalaenoptera from the late Miocene of Peru, our paleobiogeographic analysis suggests that the North Atlantic ocean played a major role as a center of origin of a number of balaenopterid clades including Protororqualus, Archaebalaenoptera and more advanced balaenopterid taxa. From a North Atlantic center of origin, two dispersal events are inferred that led to the origins of Archaebalaenoptera species in the South Pacific and Mediterranean. The distribution of Archaebalaenoptera was antitropical in the late Miocene. The role played by the Mediterranean salinity crisis is also investigated and discussed.

A new genus and species of Brychiopontiidae Humes, 1974 (Crustacea: Copepoda:Siphonostomatoida) associated with an abyssal holothurian in the NortheastPacific nodule province

Zootaxa ◽  
2008 ◽  
Vol 1866 (1) ◽  
pp. 290 ◽  
Author(s):  
RADITH MAHATMA ◽  
PEDRO MARTÍNEZ ARBIZU ◽  
VIATCHESLAV N. IVANENKO
Keyword(s):  
North Atlantic ◽  
New Genus ◽  
First Record ◽  
New Genus And Species ◽  
The North ◽  
The Pacific ◽  
The Family ◽  
Mandibular Palp ◽  
The Pacific Ocean ◽  
Abyssal Zone

A new genus and species Neobrychiopontius galeronae gen. nov. sp. nov. is described based on female specimens from the Pacific nodule province associated with the abyssal holothurian Oneirophanta cfr. setigera (Ludwig, 1894) (Elasipodida, Deimatidae). The holothurian and copepods were collected at a depth of 4978 m during the cruise “Nodinaut” (Ifremer, 17 May – 28 June 2004) on RV Atalante using a spade corer operated from the submersible Nautile. The new genus has retained a greater number of plesiomorphic characters, when compared to its closest relative the monotypic genus Brychiopontius Humes, 1974 from the abyssal zone of the North Atlantic: proximal 3 segments of antennule articulates (fused in Brychiopontius), well developed mandibular palp and inner lobe of maxilla (both absent in Brychiopontius). On the other hand the new genus has only 2 outer spines on the third exopodal segment of leg 1 (instead of 3 in Brychiopontius). Two plesiomorphic characters hitherto unknown for the order Siphonostomatoida are present in the new genus viz. the inner lobe of the first segment of the maxilla is armed with 2 setae and the first segment of the mandibular palp is armed with 1 seta. Neobrychiopontius galeronae gen. et sp. nov. is the second species of Siphonostomatoida found in association with abyssal holothurians (both belonging to the genus Oneirophanta) and represents the first record of the family Brychiopontiidae in the Pacific Ocean.

scholarly journals New Miocene Monachinae from the Western Shore of the Chesapeake Bay (Maryland, USA)

2017 ◽  
Vol 51 (3) ◽  
pp. 221-242 ◽  
Author(s):  
S. J. Rahmat ◽  
I. A. Koretsky ◽  
J. E. Osborne ◽  
A. A. Alford
Keyword(s):  
North Atlantic ◽  
Fish Fauna ◽  
Eastern United States ◽  
Aquatic Life ◽  
Low Salinity ◽  
The North ◽  
Early Oligocene ◽  
The Family ◽  
Western Shore ◽  
The North Atlantic

Abstract The Family Phocidae includes four subfamilies (Phocinae, Monachinae, Cystophorinae, and Devinophocinae) consisting of mediumto large-sized mammals that possess distinctive adaptations to semi-aquatic life. In the Miocene of the Chesapeake Group, only two subfamilies of the Family Phocidae were identified: Phocinae and Monachinae. Leptophoca, a representative of the subfamily Phocinae, appears on the eastern shore of the North Atlantic around 16 million years ago. Recently, two new monachine species, the larger Terranectes magnus (n. gen., n. sp.) and the medium-sized T. parvus (n. sp.), were recorded in the Upper Miocene of the Chesapeake Group in the Eastover Formation (7.0–6.0 Ma) and St. Marys Formation (10.0-8.0 Ma). These two distinct subfamilies of seals indicate a well-marked divergence between phocines and monachines, much earlier than 18 million years ago, as previously suggested. The Eastover Formation was deposited in a shallow embayment that covered southern Maryland, the coastal plain of Virginia, and the northeastern corner of North Carolina. The geologically older St. Marys Formation represents a tide-influenced coastal environment, with low-salinity estuaries. There was a sharp temperature decrease in the Late Miocene, indicated by a shift to a cooler-water fish fauna during St. Marys time. The Eastover Formation reflects warmer waters with relatively strong currents, significant shoals, barriers, and varied depths. Fossil evidence of earlier seals suggests that phocids originated in the North Atlantic and otarioids in the North Pacific. True seals diverged from ancient Carnivora in the early Oligocene (or earlier) in the Paratethyan / Mediterranean Basins, spread widely during the Middle Miocene and crossed westward across the Atlantic Ocean, before dispersing in the eastern United States by the Early Pliocene.

scholarly journals Impact of Agulhas Leakage on the Atlantic Overturning Circulation in the CCSM4

2014 ◽  
Vol 27 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Wilbert Weijer ◽  
Erik van Sebille
Keyword(s):  
North Atlantic ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Overturning Circulation ◽  
Climate System Model ◽  
The North ◽  
Salinity Variability ◽  
Meridional Overturning ◽  
The North Atlantic ◽  
The Impact

Abstract The impact of Agulhas leakage variability on the strength of the Atlantic meridional overturning circulation (AMOC) in the Community Climate System Model, version 4 (CCSM4) is investigated. In this model an advective connection exists that transports salinity anomalies from the Agulhas region into the North Atlantic on decadal (30–40 yr) time scales. However, there is no identifiable impact of Agulhas leakage on the strength of the AMOC, suggesting that the salinity variations are too weak to significantly modify the stratification in the North Atlantic. It is argued that this study is inconclusive with respect to an impact of Agulhas leakage on the AMOC. Salinity biases leave the South Atlantic and Indian Oceans too homogeneous, in particular erasing the observed salinity front in the Agulhas retroflection region. Consequently, salinity variability in the southeastern South Atlantic is found to be much weaker than observed.

scholarly journals A review of the genus Iridogorgia (Octocorallia: Chrysogorgiidae) and its relatives, chiefly from the North Atlantic Ocean

2007 ◽  
Vol 87 (2) ◽  
pp. 393-402 ◽  
Author(s):  
Les Watling
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
New England ◽  
North Atlantic ◽  
Deep Sea ◽  
New Genus ◽  
Growth Form ◽  
North Atlantic Ocean ◽  
The North ◽  
The North Atlantic

Exploration of the New England and Corner Rise Seamounts produced four new species of chrysogorgiid octocorals with the spiral iridogorgiid growth form. Three species are described as new in the genus Iridogorgia and one is described in the new genus Rhodaniridogorgia. Both genera have representatives in the Atlantic and Pacific Oceans. Iridogorgia magnispiralis sp. nov., is one of the largest octocorals encountered in the deep sea and seems to be widespread in the Atlantic.

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