A new Early Cretaceous articulate brachiopod from the Northwest Territories, Canada, and its paleobiogeographic significance

1990 ◽  
Vol 64 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Michael R. Sandy
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Early Cretaceous ◽  
New Record ◽  
High Latitudes ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Northwest Europe ◽  
Central Atlantic

A new terebratellid brachiopod species, Modestella jeletzkyi n. sp., is described from the Early Cretaceous of Prince Patrick Island, Northwest Territories, Canada. The occurrence extends the paleobiogeographic range of Modestella from northwest Europe into the northern high-latitudes of the North American continent. This new record of Modestella suggests brachiopod dispersal between northwest Europe and North America via the East Greenland Seaway, probably during the Albian. The occurrences of two other Cretaceous terebratellid genera, Advenina and Psilothyris, are updated. They are both homeomorphic with Modestella. Advenina, from the Tethyan and Jura regions of Europe, is now recorded from the Early Cretaceous of Sardinia. The occurrence of Psilothyris in North America and Europe is best explained by dispersal through the opening central Atlantic Ocean, indicating the continuation of Hispanic Corridor-type faunal links established during the Jurassic.

The species of Thecaphora on Compositae in North America

1982 ◽  
Vol 60 (8) ◽  
pp. 1512-1522 ◽  
Author(s):  
Rubén Durán
Keyword(s):  
New Species ◽  
North America ◽  
North American ◽  
Morphological Characteristics ◽  
American Continent ◽  
Bright Field ◽  
New Host ◽  
North American Continent ◽  
The North ◽  
Scanning Electron

Five new species of Thecaphora collected in Mexico are described, some of which are parasitic on genera of Compositae not previously reported as hosts. Species of Thecaphora on Compositae for the North American continent now total 11. New species include Thecaphora denticulata, T. heliopsidis, T. hennenea, T. melampodii, and T. neo-mexicana. New host genera for North America include Bidens, Heliopsis, and Melampodium. Morphological characteristics of Thecaphora species and taxonomic criteria to delimit them are discussed. Keys to the species, interpretations of spore ball morphology and spore sculpturing, and scanning electron and bright-field micrographs are presented.

‘Homesick for the North American Continent’: Elizabeth Bowen's Postwar Transatlantic Crossings

2021 ◽  
Vol 51 (1) ◽  
pp. 114-130
Author(s):  
Heather Corbally Bryant
Keyword(s):  
United States ◽  
North America ◽  
The United States ◽  
Eudora Welty ◽  
Central Question ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Mother And Child ◽  
The Relationship

This article investigates the influence of North America on Bowen's later work. After the war, Bowen traveled to America, at least once a year, until her last illness. Yet her time in the United States has often been overlooked. In the States, she lectured at colleges and universities across the country, and taught at several prestigious schools. She also wrote articles and essays for the more lucrative American journals and periodicals. In addition to touring the country, she was able to see her many American friends, such as Eudora Welty, and her publishers, the Knopfs, as well as her lover, Charles Ritchie. This new continent allowed Bowen to confront old traumas on new grounds, especially in the American element of Eva Trout, in which she displaces the central question of the relationship between mother and child onto American soil to interrogate the (literally, in Jeremy's case) unspeakable nature of trauma.

Hazards of the Caribbean

2005 ◽  
Author(s):  
Susan Elizabeth Hough ◽  
Roger G. Bilham
Keyword(s):  
United States ◽  
Puerto Rico ◽  
North America ◽  
Plate Tectonics ◽  
Plate Boundary ◽  
The United States ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
The Caribbean

The Caribbean is a place of romance. Idyllic beaches, buoyant cultures, lush tropical flora; even the Caribbean pirates of yore often find themselves romanticized in modern eyes, and on modern movie screens. Yet it requires barely a moment’s reflection to appreciate the enormous resilience that must exist in a place that is so routinely battered by storms of enormous ferocity. News stories tend to focus on large storms that reach the United States, but many large hurricanes arrive in the United States by way of the Caribbean. Before it slammed into South Carolina in 1989, Hurricane Hugo brushed the Caribbean islands, skimming Puerto Rico and devastating many small islands to its east. Other hurricanes have hit the islands more directly. These include Inez, which claimed some 1,500 lives in 1966, and the powerful Luis, which caused $2.5 billion in property damage and 17 deaths when it pummeled the Leeward Islands and parts of Puerto Rico and the Virgin Islands in 1995. Hurricanes also figure prominently in the pre-20th-century history of the Caribbean—storms that had no names, the sometimes lethal fury of which arrived unheralded by modern forecasts. Most people know that the Caribbean is hurricane country; probably few realize that it is earthquake country as well. After all, the western edge of North America is the active plate boundary; earthquakes occur in the more staid midcontinent and Atlantic seaboard, but far less commonly. What can be overlooked, however, is North America’s other active plate boundary. To understand the general framework of this other boundary, it is useful to return briefly to basic tenets of plate tectonics theory. As discussed in earlier chapters, the eastern edge of North America is known as a passive margin. Because the North American continent is not moving relative to the adjacent Atlantic oceanic crust, in plate tectonics terms, scientists do not differentiate between the North American continent and the western half of the Atlantic ocean.

scholarly journals Phylogenetics of a Rapid, Continental Radiation: Diversification, Biogeography, and Circumscription of the Beardtongues (Penstemon; Plantaginaceae)

2021 ◽  
Author(s):  
Andrea D Wolfe ◽  
Paul D Blischak ◽  
Laura Kubatko
Keyword(s):  
North America ◽  
Bootstrap Method ◽  
Nuclear Gene ◽  
American Continent ◽  
Broad Distribution ◽  
North American Continent ◽  
The Past ◽  
The North ◽  
Evolutionary Radiation ◽  
Founder Event

Abstract. Penstemon (Plantaginaceae), the largest genus of plants native to North America, represents a recent continental evolutionary radiation. We investigated patterns of diversification, phylogenetic relationships, and biogeography, and determined the age of the lineage using 43 nuclear gene loci. We also assessed the current taxonomic circumscription of the ca. 285 species by developing a phylogenetic taxonomic bootstrap method. Penstemon originated during the Pliocene/Pleistocene transition. Patterns of diversification and biogeography are associated with glaciation cycles during the Pleistocene, with the bulk of diversification occurring from 1.0-0.5 mya. The radiation across the North American continent tracks the advance and retreat of major and minor glaciation cycles during the past 2.5 million years with founder-event speciation contributing the most to diversification of Penstemon. Our taxonomic bootstrap analyses suggest the current circumscription of the genus is in need of revision. We propose rearrangement of subgenera, sections, and subsections based on our phylogenetic results. Given the young age and broad distribution of Penstemon across North America, it offers an excellent system for studying a rapid evolutionary radiation in a continental setting.

scholarly journals THE EFFECT OF THE GLACIAL EPOCH UPON THE DISTRIBUTION OF INSECTS IN NORTH AMERICA

1875 ◽  
Vol 7 (9) ◽  
pp. 164-167
Author(s):  
Aug. R. Grote
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
The United States ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Glacial Epoch

From the condition of an hypothesis the glacial epoch has been elevated into that of a theory by the explanations it has afforded to a certain class of geological phenomena. The present paper endeavors to show that certain zoological facts are consistent with the presence, during past times, of a vast progressive field of ice, which, in its movement from north to south, gradually extended over large portions of the North American continent. These facts, in the present instance, are furnished by a study of our Lepidoptera, or certain kinds of butterflies and moths now inhabiting the United States and adjacent territories.

Early Cretaceous brachiopods from Mexico and their paleobiogeographic significance

1990 ◽  
Vol 64 (6) ◽  
pp. 942-956 ◽  
Author(s):  
Michael R. Sandy
Keyword(s):  
Early Cretaceous ◽  
Longitudinal Distribution ◽  
Formal Description ◽  
High Latitudes ◽  
American Continent ◽  
Low Latitude ◽  
East Pacific ◽  
Bipolar Distribution ◽  
Central Atlantic ◽  
First Time

The rhynchonellid genus Ptilorhynchia Crickmay and the terebratulid genus Sellithyris Middlemiss are described from Mexico for the first time. This is the first formal description of Sellithyris from the American Continent. Ptilorhynchia (Proteorhynchia) imlayi n. sp. is described from the late Aptian of the La Penã Formation, Coahuila. “Rhynchonella’ durangensis Imlay from the Valanginian of the Carbonera Formation, Durango, is assigned to Ptilorhynchia (Proteorhynchia). “Terebratula’ coahuilensis Imlay from the Valanginian Barril Viejo Formation, Coahuila, is referred to Sellithyris. Sellithyris coahuilensis indicates close links with contemporaneous Valanginian faunas of southern Europe. During the early Early Cretaceous Sellithyris had a fairly restricted latitudinal and broad longitudinal distribution (Tethys and its extension across the opening Central Atlantic Ocean). Ptilorhynchia (Proteorhynchia) in Mexico is significant as the first low-latitude record for Ptilorhynchia. Other Lower Cretaceous records are from northern and southern high latitudes, previously interpreted as a bipolar distribution. It is suggested that Ptilorhynchia had a Boreal-East Pacific distribution with Ptilorhynchia (Proteorhynchia) being a low-latitude Early Cretaceous offshoot. The genus may prove to be pandemic. Proteorhynchia Owen is regarded as a subgenus of Ptilorhynchia.

scholarly journals Physical and chemical properties of pollution aerosol particles transported from North America to Greenland as measured during the POLARCAT summer campaign

2011 ◽  
Vol 11 (21) ◽  
pp. 10947-10963 ◽  
Author(s):  
B. Quennehen ◽  
A. Schwarzenboeck ◽  
J. Schmale ◽  
J. Schneider ◽  
H. Sodemann ◽  
...  
Keyword(s):  
North America ◽  
Black Carbon ◽  
Refractory Material ◽  
Aerosol Particles ◽  
Size Distributions ◽  
American Continent ◽  
Air Masses ◽  
Accumulation Mode ◽  
North American Continent ◽  
The North

Abstract. Within the framework of the POLARCAT-France campaign, aerosol physical, chemical and optical properties over Greenland were measured onboard the French ATR-42 research aircraft. The origins of CO excess peaks detected in the aircraft measurements then have been identified through FLEXPART simulations. The study presented here focuses particularly on the characterization of air masses transported from the North American continent to Greenland. Air masses that picked up emissions from Canadian boreal forest fires as well as from the cities on the American east coast were identified and selected for a detailed study. Measurements of CO concentrations, aerosol chemical composition, aerosol number size distributions, aerosol volume volatile fractions and aerosol light absorption (mainly from black carbon) are used in order to study the relationship between CO enhancement (ΔCO), aerosol particle concentrations and number size distributions. Aerosol number size distributions (normalised with their respective ΔCO) are in good agreement with previous studies. Nonetheless, wet scavenging may have occurred along the pathway between the emission sources and Greenland leading to a less pronounced accumulation mode in the POLARCAT data. Chemical analyses from mass spectrometry show that submicrometer aerosol particles are mainly composed of sulphate and organics. The observed bimodal (Aitken and accumulation) aerosol number size distributions show a significant enhancement in Aitken mode particles. Furthermore, results from the thermodenuder analysis demonstrate the external mixture of boreal fire (BF) air masses from North America (NA). This is particularly observed in the accumulation mode, containing a volume fraction of up to 25–30% of refractory material at the applied temperature of 280 °C. NA anthropogenic air masses with only 6% refractory material in the accumulation mode can be clearly distinguished from BF air masses. Overall, during the campaign rather small amounts of black carbon from the North American continent were transported towards Greenland during the summer POLARCAT observation period, which also is a valuable finding with respect to potential climate impacts of black carbon in the Arctic.

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