Katian (Upper Ordovician) δ13C chemostratigraphy and sequence stratigraphy in the United States and Baltoscandia: A regional comparison

2010 ◽  
Vol 296 (3-4) ◽  
pp. 217-234 ◽  
Author(s):  
Stig M. Bergström ◽  
Seth Young ◽  
Birger Schmitz
Keyword(s):  
United States ◽  
Sequence Stratigraphy ◽  
The United States ◽  
Upper Ordovician ◽  
Regional Comparison

scholarly journals Discussion Forum: The Vanishing Nineteenth Century in European History?

2018 ◽  
Vol 51 (4) ◽  
pp. 611-695
Author(s):  
Karen Hagemann ◽  
Simone Lässig
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
The United States ◽  
The State ◽  
Discussion Forum ◽  
European History ◽  
Historical Research ◽  
Multiple Perspectives ◽  
Historical Knowledge ◽  
Regional Comparison

This forum explores from multiple perspectives the often stated impression that the nineteenth century is “vanishing” from German and European history. It asks how one can explain this trend, what consequences it has for the development of historiography and public historical knowledge, if and why the nineteenth century matters for the present, and what the future of nineteenth-century history might be. Fourteen experts on different regions and historiographical approaches to European history from the United States and Germany discuss these questions. We sought contributors from these two countries in order to illuminate differences in the historical profession on either side of the Atlantic, and are sure that a broader regional comparison would point to more varieties in the state of historical research on the nineteenth century.

Cupulocrinus angustatus (Meek and Worthen, 1870), a cladid crinoid from the Upper Ordovician Maquoketa Formation of the northern midcontinent of the United States

2002 ◽  
Vol 76 (1) ◽  
pp. 109-122 ◽  
Author(s):  
James C. Brower
Keyword(s):  
United States ◽  
Correlation Coefficients ◽  
The United States ◽  
Significance Tests ◽  
Upper Ordovician ◽  
Developmental Constraints ◽  
Stratigraphic Position

Cupulocrinus angustatus (Meek and Worthen, 1870) is common and widely distributed in the Maquoketa Formation of the northern midcontinent of the United States, and specimens are known from the Isotelus and Vogdesia Zones of the Elgin, the Clermont, Fort Atkinson, and Brainard Members. Cluster significance tests indicate that crinoids from all stratigraphic horizons are conspecific. The most numerous primibrachs are located in the A and B rays, whereas the C ray exhibits the fewest plates. The largest and smallest numbers of secundibrachs occur in the B and C rays, respectively. The number of brachs is independent of stratigraphic position and the size of the crinoids. Correlation coefficients for the numbers of brachs demonstrate that the arms are divided into two overlapping and covarying levels: the proximal arms from the primibrachs to tertibrachs, and distal arms ranging from the tertibrachs to quintibrachs. Growth of the aboral cup is generally isometric or roughly so. Conversely, the width:height ratios of brachs typically increase in progressively larger individuals. Similarly, most deposition of calcite on the columnals affects their width rather than height. The correlations for the aboral cup and its plates generally exceed those of brachs and stem plates. The contrasts in allometry and integration and coordination between the aboral cup versus the brachs and column are attributed to differences in basic geometry and developmental constraints. Similar patterns are seen in other Paleozoic and perhaps all or most crinoids.

The otarionine trilobites Harpidella and Maurotarion, with species from northwestern Canada, the United States, and Australia

1995 ◽  
Vol 69 (2) ◽  
pp. 307-326 ◽  
Author(s):  
Jonathan M. Adrain ◽  
Brian D. E. Chatterton
Keyword(s):  
United States ◽  
New Species ◽  
Northwest Territories ◽  
Middle Devonian ◽  
The United States ◽  
Upper Ordovician ◽  
Mackenzie Mountains ◽  
New Diagnosis

Maurotarion Alberti, 1969, is a diverse otarionine clade that can be readily distinguished from Harpidella M'Coy, 1849. Both genera appear in the Upper Ordovician and range until the Middle Devonian. A new diagnosis for each taxon is given. New species of the genera from the Ordovician and Silurian of the central Mackenzie Mountains, Northwest Territories, Canada, include Harpidella kurrii (Ashgill), H. tikkaneni (Llandovery), H. greggi (Wenlock), and Maurotarion messieri (Llandovery). Harpidella megalops (M'Coy, 1846), H. triloba (Hu, 1975), H. spinafrons (Williams in Cooper and Williams, 1935), Maurotarion struszi (Chatterton, 1971), and M. instita (Whittington and Campbell, 1967) are revised.

Pull Factors for Direct Investment:�A Cross Regional Comparison

1980 ◽  
Vol 15 (3) ◽  
pp. 263-288 ◽  
Author(s):  
John D. Daniels ◽  
Charles J. Quigley
Keyword(s):  
United States ◽  
Latin American ◽  
United States Of America ◽  
Direct Investment ◽  
Developed Countries ◽  
The United States ◽  
Pull Factors ◽  
Regional Comparison ◽  
Investment Behaviour

Although much attention has focused on direct investment behaviour, there has been little attempt to explain why some countries receive much more than others. This study analyses differences in investment outfiows from the United States of America to different OECD, Latin American, and other lesser developed countries. A few variables explain most of the differences among each group of countries. Their identification, however, depends on the group of countries being considered.

Quintuplexacrinus, a new cladid crinoid genus from the Upper Ordovician Maquoketa Formation of the northern midcontinent of the United States

2002 ◽  
Vol 76 (6) ◽  
pp. 993-1006 ◽  
Author(s):  
James C. Brower
Keyword(s):  
United States ◽  
New Genus ◽  
Cladistic Analysis ◽  
The United States ◽  
Upper Ordovician ◽  
Axial Canal ◽  
Calcite Deposition ◽  
Very High ◽  
Distal Stem ◽  
Outer Half

Quintuplexacrinusnew genus withDendrocrinus oswegoensisMeek and Worthen (1868) as the type and only known species is described and assigned to the Merocrinidae. The new genus is characterized by a unique stem with a highly pentalobate axial canal; the distal column is highly differentiated with large and very high nodals and thin intemodals. A cladistic analysis indicates thatQuintuplexacrinusn. gen. is closely related toPraecupulocrinus.The numbers of the various orders of brachs are independent of the size and age of the animals. Within the arms only the numbers of primibrachs and secundibrachs are positively correlated. Some variation is related to position of the rays. The C ray bears the smallest number of primibrachs. The outer half-rays possess more numerous tertibrachs than the inner ones. Aboral cup growth produces a wide-based and distally expanding outline at all sizes. In general, the widths of the cup and the cup's component plates are positively allometric relative to their heights. Likewise, the width: height ratios of the proximal brachs, primibrachs through tertibrachs, increase in older and larger individuals because the widths grow faster than the heights. The number of columnals in both the proximal and distal stem regions is typically stabilized throughout ontogeny. However, the entire stem becomes longer and wider in larger specimens due to calcite deposition on the columnals. Development of the columnals is isometric so their shapes do not change with size and age.

Notes on Some Lamellibranchs from Quarrel Hill, Girvan

1946 ◽  
Vol 83 (5) ◽  
pp. 201-205 ◽  
Author(s):  
F. R. C. Reed
Keyword(s):  
United States ◽  
Special Interest ◽  
The United States ◽  
Upper Ordovician ◽  
Small Collection

A small collection of fossils from the Upper Ordovician of Quarrel Hill, Girvan, made recently by Mr. James L. Begg, is remarkable for the number and character of the lamellibranchs, several of which appear to be new. Their affinities are chiefly with those of the Ordovician of the United States and are consequently of special interest.

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