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2011

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Articles 1 - 18 of 18

Full-Text Articles in Paleontology

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell Dec 2011

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell

Sternberg Museum of Natural History Faculty Publications

The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98-65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that …


The Application Of Biostratigraphy And Paleoecology At Southern Ocean Drill Sites To Resolve Early To Middle Miocene Paleoclimatic Events, Ryan Farmer Aug 2011

The Application Of Biostratigraphy And Paleoecology At Southern Ocean Drill Sites To Resolve Early To Middle Miocene Paleoclimatic Events, Ryan Farmer

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The diatom biostratigraphy and paleoceanography of Ocean Drilling Program (ODP) Site 744 on the Southern Kerguelen Plateau, southern Indian Ocean are documented for the early to middle Miocene to improve chronostratigraphic age control for the Southern Ocean and Antarctic region. Paleoenvironmental fluctuations in the Southern Ocean are inferred from changes in fossil diatom abundance, preservation, and assemblage composition. A robust, new age model for Holes 744A and 744B is constructed using Constrained Optimization (CONOP) model ages for diatom biostratigraphic datum levels and new magnetic polarity data, which enables assessment of a nearly continuous record of paleoenvironmental change from ~20.25 to …


New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita Jul 2011

New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

An expansion of C4 grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more 13C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C3 vegetation. To explore this problem I present a compilation of bulk stable carbon (δ13C) and oxygen (δ18O) isotope values from a variety of large mammals from 6 localities that span from the late Clarendonian to the late Blancan in Nebraska. As expected, …


Taxonomic Composition, Paleoecology And Biostratigraphy Of Late Cretaceous Diatoms From Devon Island, Nunavut, Canadian High Arctic, Jakub Witkowski, David M. Harwood, Karen Chin Jun 2011

Taxonomic Composition, Paleoecology And Biostratigraphy Of Late Cretaceous Diatoms From Devon Island, Nunavut, Canadian High Arctic, Jakub Witkowski, David M. Harwood, Karen Chin

Department of Earth and Atmospheric Sciences: Faculty Publications

Upper Cretaceous sediments of the Kanguk Formation exposed in Eidsbotn and Viks Fiord grabens on Devon Island, Nunavut, Canadian High Arctic, yielded 91 fossil marine diatom species and varieties (including indeterminate taxa), representing 41 genera. Excellent preservation of the assemblages was aided by shallow burial, protection in down­faulted linear grabens, and the presence of abundant volcanic material. Planktonic species and resting spores com­prise nearly 70% of the diatom assemblage, and provided abundant food resources for the Late Cretaceous Arctic eco­system. Deposition of the approximately 225 m-thick stratigraphic sequence was predominantly in a shallow marine neritic setting, with an upward progression …


Review Of Barnum Brown: The Man Who Discovered Tyrannosaurus Rex. By Lowell Dingus And Mark A. Norell., Donald M. Henderson Apr 2011

Review Of Barnum Brown: The Man Who Discovered Tyrannosaurus Rex. By Lowell Dingus And Mark A. Norell., Donald M. Henderson

Great Plains Research: A Journal of Natural and Social Sciences

The book itself is well written, and follows Brown's life chronologically from birth to death. Along the way, the narrative delves, sometimes quite deeply, into the people and events, both American and foreign, that would have influenced Brown's life and work at the time. The reams of facts, figures, and dates in the book are meticulously referenced using the extensive archives of the AMNH. Brown was notorious for not keeping field notes, and correspondence to and from the field with his bosses, as well as annual reports, are the sources for most of the details of Brown's life while associated …


Secondary Minerals From Extrapedogenic Per Latus Acidic Weathering Environments At Geomorphic Edges, Eastern Nebraska, Usa, Robert Matthew Joeckel, K.D. Wally, B.J. Ang Clement, P.R. Hanson, J.S. Dillon, S.K. Wilson Jan 2011

Secondary Minerals From Extrapedogenic Per Latus Acidic Weathering Environments At Geomorphic Edges, Eastern Nebraska, Usa, Robert Matthew Joeckel, K.D. Wally, B.J. Ang Clement, P.R. Hanson, J.S. Dillon, S.K. Wilson

Conservation and Survey Division

Acidic weathering of the sulfidic Upper Cretaceous Carlile and Pierre Shales in Nebraska has led to the precipitation of the Al sulfate–hydroxide minerals aluminite, alunite, “basaluminite”/felsöbányaite (e.g.,), the aluminum hydroxides gibbsite and bayerite, and the rare Al phosphate hydroxide vashegyite. Kaolinite has also been produced as a result of this acidic weathering. These minerals do not appear as neoformed constituents in any extant soils in the region, and their existence underscores the ability of pyrite oxidation to produce major changes in mineralogy on a Holocene to Recent time scale. Jarosite, hydronium jarosite, gypsum, halotrichite, and melanterite also appear as secondary …


110 Years Of Avipoxvirus In The Galapagos Islands, Patricia Parker, Elizabeth Buckles, Heather Farrington, Kenneth Petren, Noah Whiteman, Robert Ricklefs, Jennifer Bollmer, Gustavo Jiménez-Uzcátegui Jan 2011

110 Years Of Avipoxvirus In The Galapagos Islands, Patricia Parker, Elizabeth Buckles, Heather Farrington, Kenneth Petren, Noah Whiteman, Robert Ricklefs, Jennifer Bollmer, Gustavo Jiménez-Uzcátegui

Biology Department Faculty Works

The role of disease in regulating populations is controversial, partly owing to the absence of good disease records in historic wildlife populations. We examined birds collected in the Galapagos Islands between 1891 and 1906 that are currently held at the California Academy of Sciences and the Zoologisches Staatssammlung Muenchen, including 3973 specimens representing species from two well-studied families of endemic passerine birds: finches and mockingbirds. Beginning with samples collected in 1899, we observed cutaneous lesions consistent with Avipoxvirus on 226 (6.3%) specimens. Histopathology and viral genotyping of 59 candidate tissue samples from six islands showed that 21 (35.6%) were positive …


A New Species Of Moropus (Mammalia, Perissodactyla, Chalicotheriodea) In The Batesland Formation, Great Plains Area Of North America, Carolyn Rounds Jan 2011

A New Species Of Moropus (Mammalia, Perissodactyla, Chalicotheriodea) In The Batesland Formation, Great Plains Area Of North America, Carolyn Rounds

Masters Theses 1911 - February 2014

The chalicothere Moropus was a rare perissodactyl present in the Great Plains region of North America through much of the Miocene. A temporal gap in named species of Moropus is present in the early Hemingfordian North American Land Mammal Age. This gap is filled by specimens currently referred to as Moropus sp. from the Batesland Formation in southwest South Dakota, and unnamed specimens of Moropus in the Runningwater Formation in northwestern Nebraska. A comparison of the fossils of Moropus nsp. from the Batesland Formation with those of previously described chalicothere species from the Greats Plains region, such as Moropus elatus, …


Late Devonian Paleontology And Paleoenvironments At Red Hill And Other Fossil Sites In The Catskill Formation Of North-Central Pennsylvania, Edward B. Daeschler, Walter L. Cressler Iii Jan 2011

Late Devonian Paleontology And Paleoenvironments At Red Hill And Other Fossil Sites In The Catskill Formation Of North-Central Pennsylvania, Edward B. Daeschler, Walter L. Cressler Iii

Earth & Space Sciences Faculty Publications

No abstract provided.


Encyclopedia Of Snow, Ice And Glaciers, Vijay P. Singh, Pratap Singh, Umesh K. Haritashya Jan 2011

Encyclopedia Of Snow, Ice And Glaciers, Vijay P. Singh, Pratap Singh, Umesh K. Haritashya

Geology Faculty Publications

The objective of this encyclopedia is to present the current state of scientific understanding of various aspects of earth’s cryosphere – snow, glaciers, ice caps, ice sheets, ice shelves, sea ice, river and lake ice, and permafrost – and their related interdisciplinary connections under one umbrella. Therefore, every effort has been made to provide a comprehensive coverage of cryosphere by including a broad array of topics, such as the atmospheric processes responsible for snow formation; snowfall observations; snow cover and snow surveys; transformation of snow to ice and changes in their properties; classification of ice and glaciers and their worldwide …


Timing, Distribution, Amount, And Style Of Cenozoic Extension In The Northern Great Basin, Christopher D. Henry, Allen J. Mcgrew, Joseph P. Colgan, Arthur W. Snoke, Matthew E. Brueseke Jan 2011

Timing, Distribution, Amount, And Style Of Cenozoic Extension In The Northern Great Basin, Christopher D. Henry, Allen J. Mcgrew, Joseph P. Colgan, Arthur W. Snoke, Matthew E. Brueseke

Geology Faculty Publications

This field trip examines contrasting lines of evidence bearing on the timing and structural style of Cenozoic (and perhaps late Mesozoic) extensional deformation in northeastern Nevada. Studies of metamorphic core complexes in this region report extension beginning in the early Cenozoic or even Late Cretaceous, peaking in the Eocene and Oligocene, and being largely over before the onset of “modern” Basin and Range extension in the middle Miocene. In contrast, studies based on low- temperature thermochronology and geologic mapping of Eocene and Miocene volcanic and sedimentary deposits report only minor, localized extension in the Eocene, no extension at all in …


Florida Straits Deglacial Temperature And Salinity Change: Implications For Tropical Hydrologic Cycle Variability During The Younger Dryas, Matthew W. Schmidt, Jean Lynch-Stieglitz Jan 2011

Florida Straits Deglacial Temperature And Salinity Change: Implications For Tropical Hydrologic Cycle Variability During The Younger Dryas, Matthew W. Schmidt, Jean Lynch-Stieglitz

OES Faculty Publications

The prevailing paradigm of abrupt climate change holds that rapid shifts associated with the most extreme climate swings of the last glacial cycle were forced by changes in the strength and northward extension of Atlantic Meridional Overturning Circulation (AMOC), resulting in an abrupt reorganization of atmospheric circulation patterns with global teleconnections. To determine the timing of tropical Atlantic atmospheric circulation changes over the past 21 ka BP, we reconstruct high resolution sea surface temperature and δ18OSW (a proxy for surface salinity) records based on Mg/Ca ratios and oxygen isotope measurements in the planktonic foraminifera Globigerinoides ruber from …


Meridional Shifts In The Marine Itcz And The Tropical Hydrologic Cycle Over The Last Three Glacial Cycles, Matthew W. Schmidt, Howard J. Spero Jan 2011

Meridional Shifts In The Marine Itcz And The Tropical Hydrologic Cycle Over The Last Three Glacial Cycles, Matthew W. Schmidt, Howard J. Spero

OES Faculty Publications

Paleoproxy studies show a strong correlation between tropical climate and high-latitude temperature variability recorded in the Greenland ice cores over the last glacial cycle. In particular, abrupt cooling events in the Greenland Ice Sheet Project II δ18O ice record appear synchronous with a southward migration of the Intertropical Convergence Zone (ITCZ) in the Atlantic, a weakening of the Indian and East Asian monsoon systems, and a strengthening of the South American monsoon system. Because this high-to-low-latitude climate teleconnection significantly alters the tropical hydrologic cycle around the globe, it plays a critical role in regulating global climate on glacial-interglacial …


Tapeworms Of Elasmobranchs (Part Iii) A Monograph On The Phyllobothriidae (Platyhelminthes, Cestoda), Timothy R. Ruhnke Jan 2011

Tapeworms Of Elasmobranchs (Part Iii) A Monograph On The Phyllobothriidae (Platyhelminthes, Cestoda), Timothy R. Ruhnke

Bulletin of the University of Nebraska State Museum

This monograph aims to provide information on the taxonomic status of all genera associated with the tetraphyllidean family Phyllobothriidae. Full treatments of the three valid species of the type genus, Phyllobothrium, in addition to the 47 valid species of Clistobothrium, Crossobothrium, Marsupiobothrium, Monorygma, Nandocestus, Orectolobicestus, Orygmatobothrium, Paraorygmatobothrium, Ruhnkecestus, and Scyphophyllidium are provided, as is a taxonomic history of the family. Of the valid genera historically associated with the family, only Phyllobothrium is considered to be an unambiguous member of the family. The genera Bibursibothrium, Calyptrobothrium, Cardiobothrium, Clistobothrium, Crossobothrium, Doliobothrium, Flexibothrium, Marsupiobothrium, Monorygma, Nandocestus, Orectolobicestus, Orygmatobothrium, Paraorygmatobothrium, Ruhnkecestus, Scyphophyllidium …


Evidence From The Florida Straits For Younger Dryas Ocean Circulation Changes, Jean Lynch-Stieglitz, Matthew W. Schmidt, William B. Curry Jan 2011

Evidence From The Florida Straits For Younger Dryas Ocean Circulation Changes, Jean Lynch-Stieglitz, Matthew W. Schmidt, William B. Curry

OES Faculty Publications

The waters passing through the Florida Straits today reflect both the western portion of the wind-driven subtropical gyre and the northward flow of the upper waters which cross the equator, compensating North Atlantic Deep Water export as part of the large-scale Atlantic meridional overturning circulation. It has been postulated from various lines of evidence that the overturning circulation was weaker during the Younger Dryas cold event of the last deglaciation. We show here that the contrast in the oxygen isotopic composition of benthic foraminiferal tests across the Florida Current is reduced during the Younger Dryas. This most likely reflects a …


Annual Outflow And Annual Inflow Of Water From/To Nebraska, 1950- 2010, Susan Olafsen-Lackey Jan 2011

Annual Outflow And Annual Inflow Of Water From/To Nebraska, 1950- 2010, Susan Olafsen-Lackey

Conservation and Survey Division

No abstract provided.


Reference List For Describing Cuttings And Cores Of Sediments And Sedimentary Rocks In Nebraska, J. T. Korus, Robert Matthew Joeckel, P. R. Hanson, J. W. Goeke, S. O. Lackey, M. B. Burbach Jan 2011

Reference List For Describing Cuttings And Cores Of Sediments And Sedimentary Rocks In Nebraska, J. T. Korus, Robert Matthew Joeckel, P. R. Hanson, J. W. Goeke, S. O. Lackey, M. B. Burbach

Conservation and Survey Division

No abstract provided.


Annual Outflow Of Water From Nebraska, 1950 - 2010, S. Olafsen-Lackey Jan 2011

Annual Outflow Of Water From Nebraska, 1950 - 2010, S. Olafsen-Lackey

Conservation and Survey Division

No abstract provided.