scholarly journals The Mighty Susquehanna—Extreme Floods in Eastern North America During the Past Two Millennia

2019 ◽  
Vol 46 (6) ◽  
pp. 3398-3407 ◽  
Author(s):  
Michael Toomey ◽  
Meagan Cantwell ◽  
Steven Colman ◽  
Thomas Cronin ◽  
Jeffrey Donnelly ◽  
...  
Keyword(s):  
North America ◽  
Eastern North America ◽  
Extreme Floods ◽  
The Past

The Past 11,000 Years of Vegetational Change in Eastern North America

BioScience ◽  
1981 ◽  
Vol 31 (7) ◽  
pp. 501-506 ◽  
Author(s):  
Thompson Webb
Keyword(s):  
North America ◽  
Eastern North America ◽  
The Past ◽  
Vegetational Change

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

2016 ◽  
Author(s):  
Chase Doran Brownstein
Keyword(s):  
United States ◽  
North America ◽  
Early Cretaceous ◽  
Fossil Record ◽  
East Coast ◽  
The United States ◽  
Eastern North America ◽  
New Taxon ◽  
Western North America ◽  
The Past

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, and only a few sediments to the east of the continent are fossiliferous. Among them is the Arundel Formation of the east coast of the United States, 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 Formation which may warrant the naming of a new taxon of dinosaur. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. 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. Comparisons between the Arundel ornithomimosaur and similar southeast Asian ornithomimosaurian material as well as ornithomimosaur remains from western North America suggest that a lineage of ornithomimosaurs with a metatarsal condition intermediate between that of basal and derived ornithomimosaurs was present through southeast Asia into North America, in turn suggesting that such animals coexisted with genera having a more primitive metatarsal morphology as seen in N. justinhofmanni.

Potential Magnitude of Future Vegetation Change in Eastern North America: Comparisons with the Past

Science ◽  
1991 ◽  
Vol 254 (5032) ◽  
pp. 692-695 ◽  
Author(s):  
J. T. OVERPECK ◽  
P. J. BARTLEIN ◽  
T. WEBB
Keyword(s):  
North America ◽  
Vegetation Change ◽  
Eastern North America ◽  
The Past

scholarly journals Differing climatic mechanisms control transient and accumulated vegetation novelty in Europe and eastern North America

2019 ◽  
Vol 374 (1788) ◽  
pp. 20190218 ◽  
Author(s):  
Kevin D. Burke ◽  
John W. Williams ◽  
Simon Brewer ◽  
Walter Finsinger ◽  
Thomas Giesecke ◽  
...  
Keyword(s):  
North America ◽  
Displacement Vector ◽  
First Century ◽  
Novel Ecosystems ◽  
Eastern North America ◽  
The Past ◽  
Climate Simulations ◽  
Mean And Variance ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Understanding the mechanisms of climate that produce novel ecosystems is of joint interest to conservation biologists and palaeoecologists. Here, we define and differentiate transient from accumulated novelty and evaluate four climatic mechanisms proposed to cause species to reshuffle into novel assemblages: high climatic novelty, high spatial rates of change (displacement), high variance among displacement rates for individual climate variables, and divergence among displacement vector bearings. We use climate simulations to quantify climate novelty, displacement and divergence across Europe and eastern North America from the last glacial maximum to the present, and fossil pollen records to quantify vegetation novelty. Transient climate novelty is consistently the strongest predictor of transient vegetation novelty, while displacement rates (mean and variance) are equally important in Europe. However, transient vegetation novelty is lower in Europe and its relationship to climatic predictors is the opposite of expectation. For both continents, accumulated novelty is greater than transient novelty, and climate novelty is the strongest predictor of accumulated ecological novelty. These results suggest that controls on novel ecosystems vary with timescale and among continents, and that the twenty-first century emergence of novelty will be driven by both rapid rates of climate change and the emergence of novel climate states. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’

scholarly journals Not With a Bang, But a Whimper: The End of the Archaic in Northeast Texas

1998 ◽  
Author(s):  
Maynard B. Cliff
Keyword(s):  
North America ◽  
Stone Tools ◽  
Archaic Period ◽  
Eastern North America ◽  
Way Of Life ◽  
The Holocene ◽  
The Past ◽  
Successful Adaptation ◽  
Local Resources ◽  
Small Band

The Archaic period in Northeast Texas lasted for thousands of years and, if this length of time can be taken as any indication, it was as an extremely successful adaptation to the Holocene environment of North America. Accepting this view, however, begs the question: "why and how did the Archaic period come to an end?" This paper uses the term "Archaic" to describe a "way of life" (see Story 1990:211), and in this sense, the Archaic period in eastern North America may be seen as a "tradition," characterized by small, band-level societies, marked by an economy based on "hunting, fishing, shell-fishing, and plant-collecting." It has often been described in the past as a period of post-Pleistocene "settling in," with increasingly intensive utilization of "local" resources. The Archaic is generally recognized by the presence of certain cultural attributes, including "large and broad-bladed dart points and ground- and polished-stone tools and ornaments." In this regard, Northeast Texas is no different from much of the rest of eastern North America.

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

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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