scholarly journals Extinction of North American Cuvieronius (Mammalia: Proboscidea: Gomphotheriidae) driven by dietary resource competition with sympatric mammoths and mastodons

Paleobiology ◽  
2020 ◽  
Vol 46 (1) ◽  
pp. 41-57
Author(s):  
Gregory James Smith ◽  
Larisa R. G. DeSantis
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
North American ◽  
Resource Competition ◽  
Feeding Strategy ◽  
Atlantic Coastal Plain ◽  
Dental Microwear ◽  
Wide Range ◽  
Alternative Hypotheses ◽  
Abundance And Diversity

AbstractThe gomphotheres were a diverse and widespread group of proboscideans occupying Eurasia, North America, and South America throughout the Neogene. Their decline was temporally and spatially heterogeneous, and the gomphotheres ultimately became extinct during the late Pleistocene; however, the genus Cuvieronius is rarely represented in late Pleistocene assemblages in North America. Two alternative hypotheses have been invoked to explain this phenomenon: (1) competitive exclusion by sympatric mammoths and mastodons or (2) ecologic displacement due to an environmental transition from closed forests to open grasslands. To test whether competition for resources contributed to the demise of North American Cuvieronius, we present herein a large collection of stable isotope and dental microwear data from populations occupying their Pleistocene refugium in the Atlantic Coastal Plain. Results suggest that Cuvieronius consumed a wide range of resources with variable textural and photosynthetic properties and was not specialized on either grasses or browse. Further, we document evidence for the consumption of similar foods between contemporaneous gomphotheres, mammoths, and mastodons. The generalist feeding strategy of the gomphotheres likely facilitated their high Miocene abundance and diversity. However, this “jack of all trades and master of none” feeding strategy may have proved challenging following the arrival of mammoths and likely contributed to the extirpation of Cuvieronius in North America.

scholarly journals A Cross-sectional Survey of the North American Skull Base Society: Current Practice Patterns of Vestibular Schwannoma Evaluation and Management in North America

2017 ◽  
Vol 79 (03) ◽  
pp. 289-296 ◽  
Author(s):  
Jamie Van Gompel ◽  
R. Wiet ◽  
Nicole Tombers ◽  
Anand Devaiah ◽  
Devyani Lal ◽  
...  
Keyword(s):  
North America ◽  
Skull Base ◽  
Vestibular Schwannoma ◽  
North American ◽  
Management Practices ◽  
Current Practice ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Number Of Patients ◽  
Wide Range

Background Very few studies have examined vestibular schwannoma (VS) management trends across centers and between providers. The objective of this study is to examine current practice trends, variance in treatment philosophies, and nuanced or controversial aspects of VS care across North America. Methods This is a cross-sectional survey of North American Skull Base Society (NASBS) members who report regular involvement in VS care. Results A total of 57 completed surveys were returned. Most respondents claimed to have over 20 years of experience and the majority reported working in an academic practice with an affiliated otolaryngology and/or neurosurgery residency program. Sixty-three percent of respondents claimed to evaluate VS patients in clinic with both an otolaryngologist and neurosurgeon involved. Eighty-six percent of respondents claimed to operate on VS with both an otolaryngologist and neurosurgeon involved, while only 18% of neurosurgeons and 9% of otolaryngologists performed surgery alone. There was a wide range in the number of cases evaluated at each center annually. Similarly, there was wide variation in the number of patients treated with microsurgery and radiation at each center. Additional details regarding management preferences for microsurgery, stereotactic radiosurgery, stereotactic radiotherapy, and conservative observation are presented. Conclusion VS management practices vary between providers and centers. Overall, most centers employ a multidisciplinary approach to management with collaboration between otolaryngology and neurosurgery. Overall, survey responses concur with previous studies suggesting a shift toward conservatism in management.

scholarly journals North American channel catfish, Ictalurus punctatus: a neglected but potentially invasive freshwater fish species?

2021 ◽  
Vol 23 (5) ◽  
pp. 1563-1576 ◽  
Author(s):  
Phillip J. Haubrock ◽  
Gordon H. Copp ◽  
Iva Johović ◽  
Paride Balzani ◽  
Alberto F. Inghilesi ◽  
...  
Keyword(s):  
North America ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
North American ◽  
Disease Transmission ◽  
Native Species ◽  
Assessment Protocol ◽  
South Italy ◽  
Wide Range ◽  
North And South

AbstractThe North American channel catfish Ictalurus punctatus has been introduced to several locations in Europe but has received little or no scientific study despite its invasive attributes, including prolific reproduction, tolerance to a wide range of conditions, opportunistic feeding, at least partial ‘predator release’, and some evidence of environmental impacts (e.g. disease transmission). To assess the species’ potential invasiveness and the likely risks to native species and ecosystems in Europe, available literature from both North America and Europe was reviewed and used to carry out risk screenings of the species for the risk assessment areas, North and South Italy, using the Aquatic Invasiveness Screening Kit (AS-ISK), which was followed by a more detailed evaluation (for both North America and Europe) of the species’ potential impacts using the Environmental Impact Classification of Alien Taxa (EICAT) assessment protocol. The AS-ISK score indicated that channel catfish is likely to pose a high risk of being invasive in both North and South Italy, with EICAT scores indicating “Major” impacts for both North America and Europe, at high and medium confidence levels, respectively. The present results emphasise the urgent need to carry out in-depth studies on introduced populations of this species to understand better its invasive potential so as to inform management decisions on the appropriate control or eradication measures for invaded water bodies.

scholarly journals The Genus Pachyma (Syn. Wolfiporia) Reinstated and Species Clarification of the Cultivated Medicinal Mushroom “Fuling” in China

2020 ◽  
Vol 11 ◽  
Author(s):  
Fang Wu ◽  
Shou-Jian Li ◽  
Cai-Hong Dong ◽  
Yu-Cheng Dai ◽  
Viktor Papp
Keyword(s):  
North America ◽  
East Asia ◽  
North American ◽  
Biological Activities ◽  
Phylogenetic Analyses ◽  
East Asian ◽  
New Combination ◽  
Medicinal Mushroom ◽  
Morphological Examination ◽  
Wide Range

The fungus “Fuling” has been used in Chinese traditional medicine for more than 2000 years, and its sclerotia have a wide range of biological activities including antitumour, immunomodulation, anti-inflammation, antioxidation, anti-aging etc. This prized medicinal mushroom also known as “Hoelen” is resurrected from a piece of pre-Linnean scientific literature. Fries treated it as Pachyma hoelen Fr. and mentioned that it was cultivated on pine trees in China. However, this name had been almost forgotten, and Poria cocos (syn. Wolfiporia cocos), originally described from North America, and known as “Tuckahoe” has been applied to “Fuling” in most publications. Although Merrill mentioned a 100 years ago that Asian Pachyma hoelen and North American P. cocos are similar but different, no comprehensive taxonomical studies have been carried out on the East Asian Pachyma hoelen and its related species. Based on phylogenetic analyses and morphological examination on both the sclerotia and the basidiocarps which are very seldomly developed, the East Asian samples of Pachyma hoelen including sclerotia, commercial strains for cultivation and fruiting bodies, nested in a strongly supported, homogeneous lineage which clearly separated from the lineages of North American Wolfiporia cocos and other species. So we confirm that the widely cultivated “Fuling” Pachyma hoelen in East Asia is not conspecific with the North American Wolfiporia cocos. Based on the changes in Art. 59 of the International Code of Nomenclature for algae, fungi, and plants, the generic name Pachyma, which was sanctioned by Fries, has nomenclatural priority (ICN, Art. F.3.1), and this name well represents the economically important stage of the generic type. So we propose to use Pachyma rather than Wolfiporia, and subsequently Pachyma hoelen and Pachyma cocos are the valid names for “Fuling” in East Asia and “Tuckahoe” in North America, respectively. In addition, a new combination, Pachyma pseudococos, is proposed. Furthermore, it seems that Pachyma cocos is a species complex, and that three species exist in North America.

scholarly journals An elongate hadrosaurid forelimb with biological traces informs the biogeography of the Lambeosaurinae

2020 ◽  
pp. 1-9
Author(s):  
Chase Doran Brownstein ◽  
Immanuel Bissell
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Cretaceous ◽  
North American ◽  
American West ◽  
Atlantic Coastal Plain ◽  
Western Interior Seaway ◽  
Terrestrial Vertebrates ◽  
Both Bones ◽  
Atlantic Coastal

Abstract Although the fossil record of the Late Cretaceous eastern North American landmass Appalachia is poor compared to that from the American West, it includes material from surprisingly aberrant terrestrial vertebrates that may represent relictual forms persisting in relative isolation until the end of the Mesozoic. One intriguing question is to what extent eastern and western North American faunas interspersed following the closure of the Western Interior Seaway during the Maastrichtian Stage of the Late Cretaceous ca. 70 Ma. Isolated remains from the Atlantic Coastal Plain in New Jersey have been preliminarily identified as the bones of crested lambeosaurine hadrosaurids, a derived clade known from the Cretaceous of Asia, western North America, and Europe, but have not been formally described. We describe the partial forelimb of a large hadrosaurid from the late Maastrichtian New Egypt Formation of New Jersey. The ulna preserves multiple deep scores identifiable as shark feeding marks, and both bones show ovoid and circular marks attributable to invertebrates. This forelimb is very similar to another partial antebrachium from the same area that shows evidence of septic arthritis. Both these specimens and a complete humerus from the same unit are closely comparable to the lower forelimbs of lambeosaurines among hadrosaurid dinosaurs. Although the absence of lambeosaurine synapomorphies observable on the New Egypt Formation forelimbs precludes their definite referral to Lambeosaurinae, they show that a morphotype of large hadrosauromorph with distinctly elongate forelimbs existed in the latest Maastrichtian of eastern North America and allow for a revision of the latest Cretaceous biogeography of crested herbivorous dinosaurs.

scholarly journals Plastic Microbead Accumulation in our Freshwaters: North American Great Lakes Assessments and Perspective

2021 ◽  
Author(s):  
Mary Torrance ◽  
Emma Gillies ◽  
Tristan Borchers ◽  
Avery Shoemaker ◽  
Christopher Barrett
Keyword(s):  
North America ◽  
Great Lakes ◽  
North American ◽  
Municipal Wastewater ◽  
Freshwater Ecosystems ◽  
Plastic Pollution ◽  
Freshwater Environment ◽  
Local Study ◽  
Ottawa River ◽  
Wide Range

The authors review recent studies conducted across the Great Lakes of North America to assess the quantity and type of microplastic waste found in these waters, sediments, and beaches. Findings from their own studies are shared, sampling plastic pollution from remote and secluded Nature Reserves in Lake Erie (ON), and the Ottawa River watershed (QC), showing significant accumulation of microbeads. Spherical ‘microbeads’ made of plastics are now ubiquitous in a wide range of personal healthcare and cleansing products, used by the average North American consumer now at upwards of quadrillions per day. Designed to be flushable, these plastic microbeads inevitably end up in municipal wastewater streams, and then to a large extent leak into our freshwater ecosystems. Recent studies throughout the important Great Lakes system of North America have reported microbeads at essentially all locations examined. On the shorelines, in surface waters, throughout water columns, and in sediments of these freshwater systems, microbeads are now ever-present, and are accumulating in significant amounts. Their small and stable shape and composition, and limited pathways to degradation produce a long lifespan, with the capacity to remain in the freshwater environment for potentially hundreds of years. This review collects and compares initial microbead studies between 2013–2021 in the Great Lakes region to provide a snapshot of the current levels and locations, and to serve as a baseline for future tracking to assess progress as the microbead contamination and accumulation problem is addressed. We as well present findings from our own local study of microplastic/bead accumulation downstream of the Great Lakes, in the St. Lawrence and Ottawa rivers near Montreal. Aspects of microbead contamination represent a unique subset of the worldwide microplastic problem, in that much control remains over their life cycle and eventual fate. Consequently, the power to address this microbead problem can rest with polymer chemists and engineers, who, armed with a better understanding of the relevant physical polymer properties of the beads that govern their movement into the aquatic environment, hold the ability to rationally redesign microbead composition and develop removal techniques.

scholarly journals Sixth NACW

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 7
Author(s):  
Kent Brown et al. (iss. eds.)
Keyword(s):  
North America ◽  
North American ◽  
Permanent Record ◽  
Wide Range

The Sixth North American Caribou workshop was attended by over 200 people from across North America, as well as four special guests from Russia. Participants were very surprised to see and hear about caribou living in large cedar forests and on mountain-tops where snow depths exceeded several meters, and the only available forage was the lichens growing on trees. We believe that the workshop was a major success with many excellent presentations and posters, as well as opportunities for the participants to meet and discuss caribou research, ecology, and management with their counterparts from across North America. These proceedings include a wide range of excellent papers that provide a permanent record of the workshop. The editors thank the authors and reviewers for their efforts to produce and review these papers.

scholarly journals Fossil and genomic evidence constrains the timing of bison arrival in North America

2017 ◽  
Vol 114 (13) ◽  
pp. 3457-3462 ◽  
Author(s):  
Duane Froese ◽  
Mathias Stiller ◽  
Peter D. Heintzman ◽  
Alberto V. Reyes ◽  
Grant D. Zazula ◽  
...  
Keyword(s):  
North America ◽  
Sea Level ◽  
Late Pleistocene ◽  
North American ◽  
Marine Isotope Stage ◽  
Mitochondrial Genomes ◽  
Subsequent Evolution ◽  
Large Mammal ◽  
Morphological Diversification ◽  
Steppe Bison

The arrival of bison in North America marks one of the most successful large-mammal dispersals from Asia within the last million years, yet the timing and nature of this event remain poorly determined. Here, we used a combined paleontological and paleogenomic approach to provide a robust timeline for the entry and subsequent evolution of bison within North America. We characterized two fossil-rich localities in Canada’s Yukon and identified the oldest well-constrained bison fossil in North America, a 130,000-y-old steppe bison, Bison cf. priscus. We extracted and sequenced mitochondrial genomes from both this bison and from the remains of a recently discovered, ∼120,000-y-old giant long-horned bison, Bison latifrons, from Snowmass, Colorado. We analyzed these and 44 other bison mitogenomes with ages that span the Late Pleistocene, and identified two waves of bison dispersal into North America from Asia, the earliest of which occurred ∼195–135 thousand y ago and preceded the morphological diversification of North American bison, and the second of which occurred during the Late Pleistocene, ∼45–21 thousand y ago. This chronological arc establishes that bison first entered North America during the sea level lowstand accompanying marine isotope stage 6, rejecting earlier records of bison in North America. After their invasion, bison rapidly colonized North America during the last interglaciation, spreading from Alaska through continental North America; they have been continuously resident since then.

scholarly journals Spatially explicit analysis sheds new light on the Pleistocene megafaunal extinction in North America

Paleobiology ◽  
2017 ◽  
Vol 43 (4) ◽  
pp. 642-655 ◽  
Author(s):  
Meaghan M. Emery-Wetherell ◽  
Brianna K. McHorse ◽  
Edward Byrd Davis
Keyword(s):  
North America ◽  
Great Lakes ◽  
Human Activity ◽  
Late Pleistocene ◽  
North American ◽  
Human Populations ◽  
Great Lakes Region ◽  
Radiocarbon Dates ◽  
The North ◽  
Primary Driver

AbstractThe late Pleistocene megafaunal extinctions may have been the first extinctions directly related to human activity, but in North America the close temporal proximity of human arrival and the Younger Dryas climate event has hindered efforts to identify the ultimate extinction cause. Previous work evaluating the roles of climate change and human activity in the North American megafaunal extinction has been stymied by a reliance on geographic binning, yielding contradictory results among researchers. We used a fine-scale geospatial approach in combination with 95 megafaunal last-appearance and 75 human first-appearance radiocarbon dates to evaluate the North American megafaunal extinction. We used kriging to create interpolated first- and last-appearance surfaces from calibrated radiocarbon dates in combination with their geographic autocorrelation. We found substantial evidence for overlap between megafaunal and human populations in many but not all areas, in some cases exceeding 3000 years of predicted overlap. We also found that overlap was highly regional: megafauna had last appearances in Alaska before humans first appeared, but did not have last appearances in the Great Lakes region until several thousand years after the first recorded human appearances. Overlap in the Great Lakes region exceeds uncertainty in radiocarbon measurements or methodological uncertainty and would be even greater with sampling-derived confidence intervals. The kriged maps of last megafaunal occurrence are consistent with climate as a primary driver in some areas, but we cannot eliminate human influence from all regions. The late Pleistocene megafaunal extinction was highly variable in timing and duration of human overlap across the continent, and future analyses should take these regional trends into account.

scholarly journals The northernmost occurrence of Chelydra serpentina in the eastern US during the Pleistocene

2016 ◽  
Author(s):  
Chase Brownstein
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Pleistocene ◽  
Ice Sheet ◽  
Eastern North America ◽  
Chelydra Serpentina ◽  
Turtle Species ◽  
Snapping Turtle ◽  
Caudal Vertebrae ◽  
Wide Range

The snapping turtle species Chelydra serpentina, which has a wide range across North America, is extremely tolerant to cold and even freezing conditions. Here, I describe a single caudal vertebrae referred to Chelydra serpentina from the Late Pleistocene of New Jersey which represents the northernmost known occurrence of the species in eastern North America and the closest known occurrence of the species to a glacier or ice sheet in the continent during the Pleistocene. The specimen, which was collected at Ramanessin Brook in Holmdel, New Jersey, affirms that the Pleistocene deposits which line the banks of the popular Cretaceous site are not taphonomically biased to preserving larger fossils and in the future may yield an assemblage of small vertebrates.

scholarly journals The northernmost occurrence of Chelydra serpentina in the eastern US during the Pleistocene

2016 ◽  
Author(s):  
Chase Brownstein
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Pleistocene ◽  
Ice Sheet ◽  
Eastern North America ◽  
Chelydra Serpentina ◽  
Turtle Species ◽  
Snapping Turtle ◽  
Caudal Vertebrae ◽  
Wide Range

The snapping turtle species Chelydra serpentina, which has a wide range across North America, is extremely tolerant to cold and even freezing conditions. Here, I describe a single caudal vertebrae referred to Chelydra serpentina from the Late Pleistocene of New Jersey which represents the northernmost known occurrence of the species in eastern North America and the closest known occurrence of the species to a glacier or ice sheet in the continent during the Pleistocene. The specimen, which was collected at Ramanessin Brook in Holmdel, New Jersey, affirms that the Pleistocene deposits which line the banks of the popular Cretaceous site are not taphonomically biased to preserving larger fossils and in the future may yield an assemblage of small vertebrates.

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