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 ◽  
The United States ◽  
Upper Ordovician

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.

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.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

Digital image acquisition, processing, and analysis in a polymer microscopy laboratory

1994 ◽  
Vol 52 ◽  
pp. 454-455
Author(s):  
Vinod K. Berry ◽  
Xiao Zhang
Keyword(s):  
United States ◽  
Image Analysis ◽  
Digital Image ◽  
Image Acquisition ◽  
Image Transmission ◽  
The United States ◽  
Quantitative Image Analysis ◽  
Quantitative Image

In recent years it became apparent that we needed to improve productivity and efficiency in the Microscopy Laboratories in GE Plastics. It was realized that digital image acquisition, archiving, processing, analysis, and transmission over a network would be the best way to achieve this goal. Also, the capabilities of quantitative image analysis, image transmission etc. available with this approach would help us to increase our efficiency. Although the advantages of digital image acquisition, processing, archiving, etc. have been described and are being practiced in many SEM, laboratories, they have not been generally applied in microscopy laboratories (TEM, Optical, SEM and others) and impact on increased productivity has not been yet exploited as well.In order to attain our objective we have acquired a SEMICAPS imaging workstation for each of the GE Plastic sites in the United States. We have integrated the workstation with the microscopes and their peripherals as shown in Figure 1.

Silence of the Land: On the Historical Irrelevance of Territory to Congressional Districting and Political Representation in the United States

2001 ◽  
Vol 15 (01) ◽  
pp. 53-87 ◽  
Author(s):  
Andrew Rehfeld
Keyword(s):  
United States ◽  
House Of Representatives ◽  
Political Representation ◽  
The United States ◽  
Representative Government ◽  
Congressional District ◽  
Congressional Districts ◽  
Communities Of Interest

Every ten years, the United States “constructs” itself politically. On a decennial basis, U.S. Congressional districts are quite literally drawn, physically constructing political representation in the House of Representatives on the basis of where one lives. Why does the United States do it this way? What justifies domicile as the sole criteria of constituency construction? These are the questions raised in this article. Contrary to many contemporary understandings of representation at the founding, I argue that there were no principled reasons for using domicile as the method of organizing for political representation. Even in 1787, the Congressional district was expected to be far too large to map onto existing communities of interest. Instead, territory should be understood as forming a habit of mind for the founders, even while it was necessary to achieve other democratic aims of representative government.

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