Revisiting the biogeography of Sideroxylon (Sapotaceae) and an evaluation of the taxonomic status of Argania and Spiniluma

2014 ◽  
Vol 27 (2) ◽  
pp. 104 ◽  
Author(s):  
Gail Stride ◽  
Stephan Nylinder ◽  
Ulf Swenson
Keyword(s):  
Central America ◽  
North Atlantic ◽  
Divergence Time ◽  
Taxonomic Status ◽  
Migration Route ◽  
Gulf Of Aden ◽  
Long Distance ◽  
The North ◽  
Water Dispersal ◽  
Mascarene Islands

Biogeography of Sideroxylon (Sapotoideae) and whether the satellite genera Argania and Spiniluma merit recognition are revisited. The hypothesis of an African origin with a subsequent migration to Central America via Europe and the North Atlantic landbridge is challenged. We analysed 58 accessions of trnH-psbA and ITS sequences in a fossil-calibrated, relaxed lognormal clock model with BEAST for phylogenetic and biogeographic inference. Argania spinosa (L.) Skeels from Morocco must be united with Sideroxylon, whereas S. discolor Radcl.-Sm. and S. oxyacanthum Baill. belong to subfamily Chrysophylloideae and may be recognised as Spiniluma. The divergence time estimate suggests that Sideroxylon originated and first diversified in Central America 56.3–52.2 million years ago, contemporaneous with the landbridge, but an archipelago of islands and the Tethys Seaway halted eastward expansion to Africa until c.20 million years ago, i.e. 25 million years after establishment in Africa. Range expansion of Sideroxylon was therefore not powered by the landbridge, and a long-distance dispersal from Central America to Africa is proposed. The establishment of the Gomphotherium landbridge between Africa and Eurasia at 19 million years ago provided a land-migration route to Europe and Asia, which is reconcilable with the extension of Xantolis into Asia. Sideroxylon has colonised Socotra by over-water dispersal in the Gulf of Aden, Macaronesia, Madagascar and the Mascarene Islands.

scholarly journals The Combined Effects of SST and the North Atlantic Subtropical High-Pressure System on the Atlantic Basin Tropical Cyclone Interannual Variability

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 329
Author(s):  
Albenis Pérez-Alarcón ◽  
José C. Fernández-Alvarez ◽  
Rogert Sorí ◽  
Raquel Nieto ◽  
Luis Gimeno
Keyword(s):  
High Pressure ◽  
Interannual Variability ◽  
Central America ◽  
North Atlantic ◽  
The West ◽  
The Bahamas ◽  
Pressure System ◽  
North Atlantic Subtropical High ◽  
The North ◽  
The North Atlantic

The combined effect of the sea surface temperature (SST) and the North Atlantic subtropical high-pressure system (NASH) in the interannual variability of the genesis of tropical cyclones (TCs) and landfalling in the period 1980–2019 is explored in this study. The SST was extracted from the Centennial Time Scale dataset from the National Oceanic and Atmospheric Administration (NOAA), and TC records were obtained from the Atlantic Hurricane Database of the NOAA/National Hurricane Center. The genesis and landfalling regions were objectively clustered for this analysis. Seven regions of TC genesis and five for landfalling were identified. Intercluster differences were observed in the monthly frequency distribution and annual variability, both for genesis and landfalling. From the generalized least square multiple regression model, SST and NASH (intensity and position) covariates can explain 22.7% of the variance of the frequency of TC genesis, but it is only statistically significant (p < 0.1) for the NASH center latitude. The SST mostly modulates the frequency of TCs formed near the West African coast, and the NASH latitudinal variation affects those originated in the Lesser Antilles arc. For landfalling, both covariates explain 38.7% of the variance; however, significant differences are observed in the comparison between each region. With a statistical significance higher than 90%, SST and NASH explain 33.4% of the landfalling variability in the archipelago of the Bahamas and central–eastern region of Cuba. Besides, landfalls in the Gulf of Mexico and Central America seem to be modulated by SST. It was also found there was no statistically significant relationship between the frequency of genesis and landfalling with the NASH intensity. However, the NASH structure modulates the probability density of the TCs trajectory that make landfall once or several times in their lifetime. Thus, the NASH variability throughout a hurricane season affects the TCs trajectory in the North Atlantic basin. Moreover, we found that the landfalling frequency of TCs formed near the West Africa coast and the central North Atlantic is relatively low. Furthermore, the SST and NASH longitude center explains 31.6% (p < 0.05) of the variance of the landfalling intensity in the archipelago of the Bahamas, while the SST explains 26.4% (p < 0.05) in Central America. Furthermore, the 5-year moving average filter revealed decadal and multidecadal variability in both genesis and landfalling by region. Our findings confirm the complexity of the atmospheric processes involved in the TC genesis and landfalling.

Edges and interactions beyond Europe

2018 ◽  
Author(s):  
Peter S. Wells ◽  
Naoise Mac Sweeney
Keyword(s):  
North America ◽  
Iron Age ◽  
North Atlantic ◽  
Cultural Practices ◽  
Raw Materials ◽  
Long Distance ◽  
The North ◽  
First Millennium ◽  
Temperate Europe ◽  
The North Atlantic

Iron Age Europe, once studied as a relatively closed, coherent continent, is being seen increasingly as a dynamic part of the much larger, interconnected world. Interactions, direct and indirect, with communities in Asia, Africa, and, by the end of the first millennium AD, North America, had significant effects on the peoples of Iron Age Europe. In the Near East and Egypt, and much later in the North Atlantic, the interactions can be linked directly to historically documented peoples and their rulers, while in temperate Europe the evidence is exclusively archaeological until the very end of the prehistoric Iron Age. The evidence attests to often long-distance interactions and their effects in regard to the movement of peoples, and the introduction into Europe of raw materials, crafted objects, styles, motifs, and cultural practices, as well as the ideas that accompanied them.

Palaeo-oceanography, margin stratigraphy and palaeophysiography of the Tertiary North Atlantic and Norwegian-Greenland seas

1980 ◽  
Vol 294 (1409) ◽  
pp. 177-185 ◽  
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Global Climate ◽  
Circulation Pattern ◽  
The Arctic ◽  
Continental Margins ◽  
Long Distance ◽  
Sea Level Fluctuations ◽  
The North ◽  
Border Zones

The Tertiary was a period of dramatic changes of the palaeo-oceanography of the world’s oceans in general and of the North Atlantic in particular. These changes were caused by (1) the bathymetric evolution of ocean basins and intrabasin pathways (opening of the Norwegian-Greenland Seas and of the pathway to the Arctic Ocean, interruption of the circumglobal equatorial seaway); (2) the geographical development of the oceans and adjacent marginal basins in the context of rapid and intensive eustatic sea level fluctuations; and (3) the deterioration of the global climate throughout the Tertiary (change from a non-glacial to a glacial world, causing major changes in circulation of the surface and deep water). A biostratigraphy of Tertiary sediments deposited close to the continental margins has been developed by using remains of planktonic floras and faunas. Their presence in these sediments and their usefulness for long distance correlations of margin sediments, depend upon the circulation pattern and hydrographic gradients of the oceanic surface and deep water masses, the climatic regime over the continental border zones, and the probability of their post-depositional preservation.

Review of Sarcotretes Jungersen, 1911 (Copepoda: Pennellidae) from midwater and demersal fishes in the north Atlantic Ocean

1988 ◽  
Vol 66 (6) ◽  
pp. 1371-1375 ◽  
Author(s):  
W. E. Hogans
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Type Species ◽  
North Atlantic Ocean ◽  
Taxonomic Status ◽  
Nominal Species ◽  
Parasitic Copepods ◽  
The North ◽  
The North Atlantic ◽  
Demersal Fishes

The genus Sarcotretes, parasitic copepods from midwater and demersal fishes in the Atlantic Ocean, is reviewed. The taxonomic status of the six nominal species is discussed. Two species, S. scopeli, from midwater fishes, and S. eristaliformis, from demersal fishes, are tentatively considered valid members of the genus. The remaining species (S. inflexus, S. lobatus, S. gempyli, and S. nodicornis) are probable synonyms of the type species, S. scopeli. A detailed description of S. scopeli from six midwater host species is presented.

A monograph of the calcareous sponges (Porifera, Calcarea) of Greenland

2013 ◽  
Vol 95 (7) ◽  
pp. 1395-1459 ◽  
Author(s):  
Hans Tore Rapp
Keyword(s):  
Transition Zone ◽  
North Atlantic ◽  
New Records ◽  
Taxonomic Status ◽  
Northern Coast ◽  
Calcareous Sponges ◽  
The North ◽  
Higher Taxa ◽  
History Of ◽  
The North Atlantic

Greenland has more than 200 years of history of studies of the sponge fauna and is the type locality for a number of species. Many of these have not been encountered since, and as the type material has been hard to find or even lost, their taxonomic status has remained uncertain. In this study all species of calcareous sponges previously reported from Greenland are reviewed. The revision is based predominantly on new or unidentified material collected during various expeditions, but also on material used by previous authors. This includes samples from all coasts of Greenland, from the southernmost Kap Farvel area to Peary Land on the northern coast, some of the northernmost records of calcareous sponges ever. Greenland is a transition zone between the western and eastern Atlantic boreal calcareous sponge faunas, being home to species from both sides of the North Atlantic combined with some true Arctic species. There is also a strong link between the Canadian and Greenlandic sponge faunas. Twenty-eight species have been identified, from which six are new to Greenland and one is new to science. New records for Greenland are: Clathrina arnesenae (Rapp, 2006); Clathrina camura (Rapp, 2006); Clathrina pellucida (Rapp, 2006); Sycon abyssale Borojevic & Graat-Kleeton, 1965; Leucandra valida Lambe, 1900; and Sycettusa thompsoni (Lambe, 1900). Clathrina tendali sp. nov. has been described from western Greenland and Leucosolenia corallorrhiza (Haeckel, 1872) and Leucandra penicillata (Schmidt, 1869) have been resurrected. Keys for identification of higher taxa and the different species of Greenlandic Calcarea are provided.

scholarly journals A new large-bodied Pliocene seal with unusual cutting teeth

2020 ◽  
Vol 7 (11) ◽  
pp. 201591
Author(s):  
James P. Rule ◽  
Justin W. Adams ◽  
Douglass S. Rovinsky ◽  
David P. Hocking ◽  
Alistair R. Evans ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North Atlantic ◽  
Taxonomic Status ◽  
Diagnostic Value ◽  
New Taxon ◽  
Ancestral State ◽  
The North ◽  
Body Sizes ◽  
The Usa ◽  
The North Atlantic

Today, monachine seals display the largest body sizes in pinnipeds. However, the evolution of larger body sizes has been difficult to assess due to the murky taxonomic status of fossil seals, including fossils referred to Callophoca obscura , a species thought to be present on both sides of the North Atlantic during the Neogene. Several studies have recently called into question the taxonomic validity of these fossils, especially those from the USA, as the fragmentary lectotype specimen from Belgium is of dubious diagnostic value. We find that the lectotype isolated humerus of C. obscura is too uninformative; thus, we designate C. obscura as a nomen dubium. More complete cranial and postcranial specimens from the Pliocene Yorktown Formation are described as a new taxon, Sarcodectes magnus . The cranial specimens display adaptations towards an enhanced ability to cut or chew prey that are unique within Phocidae, and estimates indicate S. magnus to be around 2.83 m in length. A parsimony phylogenetic analysis found S. magnus is a crown monachine. An ancestral state estimation of body length indicates that monachines did not have a remarkable size increase until the evolution of the lobodontins and miroungins.

scholarly journals Local and remote moisture sources for extreme precipitation: a study of the two famous 1982 Western Mediterranean episodes

2018 ◽  
Author(s):  
Damián Insua-Costa ◽  
Gonzalo Miguez-Macho ◽  
María Carmen Llasat
Keyword(s):  
North Atlantic ◽  
Extreme Event ◽  
Wrf Model ◽  
Western Mediterranean ◽  
Central Mediterranean ◽  
Long Distance ◽  
Moisture Sources ◽  
The North ◽  
Adverse Weather ◽  
The North Atlantic

Abstract. Floods and flash floods are frequent in the South of Europe resulting from heavy rainfall events that often produce more than 200 mm in less than 24 h. Even though the meteorological conditions favorable for these situations have been widely studied, there is a lingering question that still arises: which are the sources of humidity that could explain so much precipitation? To answer this question, the regional atmospheric Weather Research and Forecasting (WRF) Model with a recently implemented moisture tagging capability has been used to analyze the main moisture sources in two famous flood events occurred during the autumn of 1982 (October and November) in the Western Mediterranean area, which is regularly affected by this type of adverse weather episodes. The procedure consists in selecting a priori potential moisture source regions for the considered extreme event, and then performing simulations with the tagging technique to quantify the relative contribution of each selected source to total precipitation. For these events we study the influence of four possible potential sources: 1) evaporation in the Western Mediterranean; 2) evaporation in the Central Mediterranean; 3) evaporation in the North Atlantic; 4) advection from the tropical and subtropical Atlantic and Africa. Results show that these four moisture sources explain most of the accumulated precipitation, with the tropical and subtropical input being the most relevant in both cases. In the October event, evaporation in the Western and Central Mediterranean and in the North Atlantic also had an important contribution. In the November episode, however, tropical and subtropical moisture accounted for more than half of the total accumulated rainfall, while evaporation in the Western Mediterranean and North Atlantic played a secondary role and the contribution of the Central Mediterranean was almost negligible. Remote sources were therefore crucial: in the October event they played a similar role to local sources while in the November case they were clearly dominant. In both episodes, long distance moisture transport from the tropics and subtropics occurred mostly in mid tropospheric layers, through well-defined moisture plumes with maximum mixing ratios at medium levels.

Nonanadromous and anadromous Atlantic salmon differ in orientation responses to magnetic displacements

2020 ◽  
Vol 77 (11) ◽  
pp. 1846-1852
Author(s):  
David Minkoff ◽  
Nathan F. Putman ◽  
Jelle Atema ◽  
William R. Ardren
Keyword(s):  
Magnetic Field ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
North Atlantic ◽  
Native Range ◽  
Long Distance ◽  
The North ◽  
Marine Migration ◽  
Displacement Experiments ◽  
The North Atlantic

Many animals undertaking long-distance migrations use Earth’s magnetic field as a “map” to assess their position for orientation. This phenomenon been particularly well-studied in salmonids using “magnetic displacement” experiments, in which animals are presented with magnetic field conditions that are characteristic of other geographic locations. However, whether use of magnetic map cues differs among populations of salmon has not been investigated. Here we show that nonanadromous and anadromous populations of Atlantic salmon (Salmo salar) raised under the same conditions within their native range differ in their response to magnetic displacements in the North Atlantic. The directions adopted by anadromous salmon juveniles to each of the magnetic displacements would support their migration from the eastern US to western Greenland, had the fish actually been at those locations. In contrast, nonanadromous salmon did not appear to respond to the magnetic displacements. The findings are consistent with the hypothesis that the innate magnetic map of anadromous salmon is adapted to guide their marine migration.

scholarly journals The state of knowledge on the deglaciation of America in 2017

2017 ◽  
Vol 43 (2) ◽  
pp. 361
Author(s):  
D. Palacios
Keyword(s):  
Central America ◽  
North Atlantic ◽  
Mountain Range ◽  
Arid Areas ◽  
Special Issue ◽  
The North ◽  
The Andes ◽  
The North Atlantic ◽  
The Antarctic ◽  
The Impact

This work presents a summary of all contributions included in this Special Issue on the deglaciation of America. It analyses the differences and coincidences between the phases of glacial evolution and their chronology in each of the regions studied, and seeks a possible explanation for asynchronies, according to the opinions of the authors of the contributions. Most of the papers show significant diversity within each region due to local factors and different approaches to their study. Often, local differences are even more important than differences with other regions. In North and Central America glacial evolution appears quite uniform, in line with the evolution of the temperature in the North Atlantic. The differences found between some regions may be due to slight variations in the impact of the temperature of the Atlantic in each region, and to differences in approaching their study. The glacial evolution of the Andes presents a greater diversity, probably due to the existence of arid areas along most of the mountain range, which show a greater sensitivity to the reception of humidity than to temperature in their glacial balance. In general, researchers have detected an attenuation of the influence of the temperature of the North Atlantic towards the south, and of the Antarctic Cold Reversal towards the north.

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