Redescription of Arundel formation Ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an “Ostrich Dinosaur”: Biogeographic implications

10.7287/peerj.preprints.2308v2 ◽

2016 ◽

Author(s):

Chase Doran Brownstein

Keyword(s):

North America ◽

Northern Hemisphere ◽

Early Cretaceous ◽

Fossil Record ◽

Eastern North America ◽

Prince George's County ◽

The Past ◽

First Time ◽

Eastern Seaboard

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, especially since few formations from the east are fossiliferous. Among those that are is the Arundel Formation of the eastern seaboard, which has produced among the best dinosaur faunas known from the Early Cretaceous of eastern North America. The diverse dinosaur fauna of this formation has been thoroughly discussed previously, but few of the dinosaur species originally described from the Arundel are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this formation are those referred to ornithomimosaurs. Here, I redescribe ornithomimosaur remains from the Arundel facies of Prince George’s County, Maryland which may be from two distinct ornithomimosaur taxa. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. Recent discoveries of small theropod material from the Arundel Formation are also reviewed and described for the first time. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaur Nedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaurian dinosaur rather than a “generalized” coelurosaur as which it was originally described. Comparisons between the Arundel ornithomimosaur material and similar Asian and European specimens suggest that both extremely basal ornithomimosaurs and more intermediate or derived forms coexisted throughout the northern hemisphere during the Early Cretaceous. Additionally, the possible presence of two distinct ornithomimosaurs in the Arundel allies the Arundel facies with Asian sediments in their coelurosaurian fauna.

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Redescription of Arundel formation Ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an “Ostrich Dinosaur”: Biogeographic implications

10.7287/peerj.preprints.2308 ◽

2016 ◽

Author(s):

Chase Doran Brownstein

Keyword(s):

North America ◽

Northern Hemisphere ◽

Early Cretaceous ◽

Fossil Record ◽

Eastern North America ◽

Prince George's County ◽

The Past ◽

First Time ◽

Eastern Seaboard

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, especially since few formations from the east are fossiliferous. Among those that are is the Arundel Formation of the eastern seaboard, which has produced among the best dinosaur faunas known from the Early Cretaceous of eastern North America. The diverse dinosaur fauna of this formation has been thoroughly discussed previously, but few of the dinosaur species originally described from the Arundel are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this formation are those referred to ornithomimosaurs. Here, I redescribe ornithomimosaur remains from the Arundel facies of Prince George’s County, Maryland which may be from two distinct ornithomimosaur taxa. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. Recent discoveries of small theropod material from the Arundel Formation are also reviewed and described for the first time. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaur Nedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaurian dinosaur rather than a “generalized” coelurosaur as which it was originally described. Comparisons between the Arundel ornithomimosaur material and similar Asian and European specimens suggest that both extremely basal ornithomimosaurs and more intermediate or derived forms coexisted throughout the northern hemisphere during the Early Cretaceous. Additionally, the possible presence of two distinct ornithomimosaurs in the Arundel allies the Arundel facies with Asian sediments in their coelurosaurian fauna.

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Description of Arundel Clay ornithomimosaur material and a reinterpretation ofNedcolbertia justinhofmannias an “Ostrich Dinosaur”: biogeographic implications

PeerJ ◽

10.7717/peerj.3110 ◽

2017 ◽

Vol 5 ◽

pp. e3110 ◽

Cited By ~ 4

Author(s):

Chase Doran Brownstein

Keyword(s):

North America ◽

Northern Hemisphere ◽

Early Cretaceous ◽

Fossil Record ◽

Eastern North America ◽

Prince George's County ◽

Stratigraphic Unit ◽

The Past ◽

First Time ◽

Eastern Seaboard

The fossil record of dinosaurs from the Early Cretaceous of Eastern North America is scant, especially since a few stratigraphic units from the east are fossiliferous. Among these stratigraphic units, the Arundel Clay of the eastern seaboard has produced the best-characterized dinosaur faunas known from the Early Cretaceous of Eastern North America. The diverse dinosaur fauna of the Arundel Clay has been thoroughly discussed previously, but a few of the dinosaur species originally described from the Arundel Clay are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this stratigraphic unit are those referred to ornithomimosaurs. Here, the researcher describes ornithomimosaur remains from the Arundel Clay of Prince George’s County, Maryland which may be from two distinct ornithomimosaur taxa. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. Recent discoveries of small theropod material from the Arundel Clay possibly belonging to ornithomimosaurs are also reviewed and described for the first time. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaurNedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaur rather than a “generalized” coelurosaur as it was originally described. Comparisons between the Arundel ornithomimosaur material and similar Asian and European specimens suggest that both extremely basal ornithomimosaurs and more intermediate or derived forms may have coexisted throughout the northern hemisphere during the Early Cretaceous.

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A comparison of earthquake damage areas as a function of magnitude across the United States

Bulletin of the Seismological Society of America ◽

10.1785/bssa0830041064 ◽

1993 ◽

Vol 83 (4) ◽

pp. 1064-1080 ◽

Cited By ~ 4

Author(s):

G. A. Bollinger ◽

M. C. Chapman ◽

M. S. Sibol

Keyword(s):

United States ◽

North America ◽

Ground Motion ◽

Epicentral Distance ◽

The United States ◽

Western United States ◽

Eastern North America ◽

Similar Response ◽

Eastern United States ◽

The West

Abstract This study investigates the relationship between earthquake magnitude and the size of damage areas in the eastern and western United States. To quantify damage area as a function of moment magnitude (M), 149 MMI VI and VII areas for 109 earthquakes (88 in the western United States, 21 in the eastern United States and Canada) were measured. Regression of isoseismal areas versus M indicated that areas in the East were larger than those in the West, at both intensity levels, by an average 5 × in the M 4.5 to 7.5 range. In terms of radii for circles of equivalent area, these results indicate that damaging ground motion from shocks of the same magnitude extend 2 × the epicentral distance in eastern North America compared to the West. To determine source and site parameters consistent with the above results, response spectral levels for eastern North America were stochastically simulated and compared with response spectral ordinates derived from recorded strong ground motion data in the western United States. Stress-drop values of 200 bars, combined with a surficial 2-km-thick low velocity “sedimentary” layer over rock basement, produced results that are compatible with the intensity observations, i.e., similar response spectral levels in the east at approximately twice their epicentral distance in the western U.S. distance. These results suggest that ground motion modeling in eastern North America may need to incorporate source and site parameters different from those presently in general use. The results are also of importance to eastern U.S. hazard assessments as they require allowance for the larger damage areas in preparedness and mitigation programs.

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Section II. Prospects for North America and Japan

National Institute Economic Review ◽

10.1177/002795019816500107 ◽

1998 ◽

Vol 165 ◽

pp. 43-53

Author(s):

Nigel Pain

Keyword(s):

United States ◽

North America ◽

Private Sector ◽

Labour Market ◽

Unemployment Rate ◽

Economic Activity ◽

The United States ◽

Equity Prices ◽

The Past

Economic activity accelerated sharply in the United States at the beginning of this year. GDP rose by 1¼ per cent in the first quarter, to a level 3.8 per cent higher than a year earlier. This was the fastest quarterly growth for two years. The acceleration in growth was unexpected given that the present cyclical expansion has now lasted for over seven years. Private sector demand is still continuing to be supported by the sustained appreciation in equity prices over the past three years, and the appreciation of the dollar has helped to hold down the inflationary pressures that are being built up as the labour market begins to tighten. The unemployment rate fell to 4.3 per cent in April, the lowest rate since 1970.

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Impacts of the North Atlantic Oscillation on Winter Precipitations and Storm Track Variability in Southeast Canada and Northeast US

10.5194/wcd-2020-20 ◽

2020 ◽

Author(s):

Julien Chartrand ◽

Francesco Salvatore Rocco Pausata

Keyword(s):

United States ◽

North America ◽

North Atlantic Oscillation ◽

North Atlantic ◽

Storm Track ◽

The United States ◽

Eastern North America ◽

The North ◽

The North Atlantic ◽

The North Atlantic Oscillation

Abstract. The North Atlantic Oscillation (NAO) affects atmospheric variability from eastern North America to Europe. Although the link between the NAO and winter precipitations in the eastern North America have been the focus of previous work, only few studies have hitherto provided clear physical explanations on these relationships. In this study we revisit and extend the analysis of the effect of the NAO on winter precipitations over a large domain covering southeast Canada and the northeastern United States. Furthermore, here we use the recent ERA5 reanalysis dataset (1979–2018), which currently has the highest available horizontal resolution for a global reanalysis (0.25°), to track extratropical cyclones to delve into the physical processes behind the relationship between NAO and precipitation, snowfall, snowfall-to-precipitation ratio (S/P), and snow cover depth anomalies in the region. In particular, our results show that positive NAO phases are associated with less snowfall over a wide region covering Nova Scotia, New England and the Mid-Atlantic of the United States relative to negative NAO phases. Henceforth, a significant negative correlation is also seen between S/P and the NAO over this region. This is due to a decrease (increase) in cyclogenesis of coastal storms near the United States east coast during positive (negative) NAO phases, as well as a northward (southward) displacement of the mean storm track over North America.

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New records of theropods from the latest Cretaceous of New Jersey and the Maastrichtian Appalachian fauna

Royal Society Open Science ◽

10.1098/rsos.191206 ◽

2019 ◽

Vol 6 (11) ◽

pp. 191206 ◽

Cited By ~ 2

Author(s):

Chase Doran Brownstein

Keyword(s):

New Jersey ◽

North America ◽

Fossil Record ◽

New Records ◽

The Other ◽

Eastern North America ◽

Western North America ◽

Northeastern North America ◽

Terrestrial Vertebrate ◽

Postcranial Remains

The faunal changes that occurred in the few million years before the Cretaceous–Palaeogene extinction are of much interest to vertebrate palaeontologists. Western North America preserves arguably the best fossil record from this time, whereas terrestrial vertebrate fossils from the eastern portion of the continent are usually limited to isolated, eroded postcranial remains. Examination of fragmentary specimens from the American east, which was isolated for the majority of the Cretaceous as the landmass Appalachia, is nonetheless important for better understanding dinosaur diversity at the end of the Mesozoic. Here, I report on two theropod teeth from the Mount Laurel Formation, a lower-middle Maastrichtian unit from northeastern North America. One of these preserves in detail the structure of the outer enamel and resembles the dentition of the tyrannosauroid Dryptosaurus aquilunguis among latest Cretaceous forms in being heavily mediolaterally compressed and showing many moderately developed enamel crenulations. Along with previously reported tyrannosauroid material from the Mt Laurel and overlying Cretaceous units, this fossil supports the presence of non-tyrannosaurid tyrannosauroids in the Campanian–Maastrichtian of eastern North America and provides evidence for the hypothesis that the area was still home to relictual vertebrates through the end of the Mesozoic. The other tooth is assignable to a dromaeosaurid and represents both the youngest occurrence of a non-avian maniraptoran in eastern North America and the first from the Maastrichtian reported east of the Mississippi. This tooth, which belonged to a 3–4 m dromaeosaurid based on size comparisons with the teeth of taxa for which skeletons are known, increases the diversity of the Maastrichtian dinosaur fauna of Appalachia. Along with previously reported dromaeosaurid teeth, the Mt Laurel specimen supports the presence of mid-sized to large dromaeosaurids in eastern North America throughout the Cretaceous.

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William Maclure and the Library of the Academy of Natural Sciences of Philadelphia

Earth Sciences History ◽

10.17704/eshi.19.1.263415807337827r ◽

2000 ◽

Vol 19 (1) ◽

pp. 33-35 ◽

Cited By ~ 1

Author(s):

John Sinkankas

Keyword(s):

United States ◽

North America ◽

The United States ◽

Natural Sciences ◽

Research Note ◽

Eastern North America ◽

On Line ◽

Geological Map ◽

Academy Of Natural Sciences

William Maclure (1763-1840) established a reputation as a geologist and mineralogist in the United States, based largely on his well-known geological map of eastern North America, published in 1809. This research note discusses the important library of over 5,000 scientific books amassed by Maclure. Many of these books are now in the collection of the Academy of Natural Sciences of Philadelphia. [Editor's note: The on-line catalog of the Academy's library is at http://www.acnatsci.org/library.]

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CHIRONOMIDAE (DIPTERA) ASSOCIATED WITH MYRIOPHYLLUM SPICATUM IN OKANAGAN VALLEY LAKES, BRITISH COLUMBIA

The Canadian Entomologist ◽

10.4039/ent1151545-11 ◽

1983 ◽

Vol 115 (11) ◽

pp. 1545-1546 ◽

Cited By ~ 11

Author(s):

B.J. Kangasniemi ◽

D. R. Oliver

Keyword(s):

United States ◽

Nineteenth Century ◽

British Columbia ◽

North America ◽

Myriophyllum Spicatum ◽

The United States ◽

Eastern North America ◽

Aquatic Weed ◽

Okanagan Valley

Eurasian water milfoil, Myriophyllum spicatum Linnaeus, was introduced into eastern North America late in the nineteenth century. It has spread and developed into a major aquatic weed in many areas of the United states and Canada (Aiken et al. 1979; Reed 1977). In British Columbia, it was first observed in the Vernon Arm of Okanagan Lake in 1970 and had spread to all major 1,akes in the Okanagan Valley by 1976 (Newroth 1979).

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NEWLY DETECTED EXOTIC SPECIES OF XYLEBORUS (COLEOPTERA: SCOLYTIDAE) WITH A REVISED KEY TO SPECIES IN EASTERN NORTH AMERICA

The Canadian Entomologist ◽

10.4039/ent12293-1 ◽

1990 ◽

Vol 122 (1) ◽

pp. 93-104 ◽

Cited By ~ 22

Author(s):

Thomas H. Atkinson ◽

Robert J. Rabaglia ◽

Donald E. Bright

Keyword(s):

United States ◽

North America ◽

Exotic Species ◽

The United States ◽

Eastern North America ◽

Key To Species ◽

Eastern Asia ◽

Ambrosia Beetles ◽

Asian Origin ◽

Large Numbers

AbstractTwo exotic species of Xyleborus (Coleoptera: Scolytidae) of Asian origin have recently been detected in the United States. Xyleborus pelliculosus Eichhoff has been collected in Pennsylvania and Maryland, and X. atratus Eichhoff from Tennessee, Georgia, Maryland, Virginia, and West Virginia. Descriptions of both species and a revised, illustrated key to members of the genus Xyleborus in eastern North America are presented. An explanation is proposed for the large numbers of recent introductions of exotic ambrosia beetles from eastern Asia into eastern North America.

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