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Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting 2016 University of Nebraska-Lincoln

Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting

Dissertations & Theses in Earth and Atmospheric Sciences

Most amphibians and reptiles (excluding birds) are poikilothermic; their internal body temperature varies with that of their external environment. This makes them useful as climate proxies, especially when linked to geographic distributions of ambient climate. I evaluate the utility of the extant crocodylian genus Alligator as a paleoclimate proxy for the Central Great Plains (CGP) using species distribution modeling. Alligator is a readily identifiable taxon with a good CGP fossil record during the Neogene (~23–2.6 Ma). Alligator first appeared in the CGP in the late Eocene (~37 Ma), was absent during most of the Oligocene, reappeared in the ...


On The Aquatic Habits Of Sauropods – An Antiquated Theory In Need Of Revival?, Michael D. Sprague 2016 Cedarville University

On The Aquatic Habits Of Sauropods – An Antiquated Theory In Need Of Revival?, Michael D. Sprague

The Research and Scholarship Symposium

When sauropods were first discovered, they were thought to have been restricted to life in the water due to their immense size. This image of sauropods was dismissed in the 1950’s when it was determined that the lungs would have been placed under massive amounts of pressure at these depths, rendering breathing nearly impossible (Kermack, 1951). However, these experiments failed to consider pneumaticity of sauropod vertebrae and were later dismissed. Sauropods possessed pneumatic features in all their presacral vertebrae, originally identified as weight-saving structures. These features kept the strength and integrity of the bone while dramatically reducing its weight ...


Microstructures Produced By Hadrosaur Bones From Alaska And Wyoming, Mark P. Guilliams, Samantha J. Lefaive, Michael D. Sprague 2016 Cedarville University

Microstructures Produced By Hadrosaur Bones From Alaska And Wyoming, Mark P. Guilliams, Samantha J. Lefaive, Michael D. Sprague

The Research and Scholarship Symposium

Since 2005 when Dr. Mary Schweitzer made the first discovery, microstructures with the appearance of “osteocytes” and “blood vessels” have been recovered from fossils of various localities, dating back as far as the Triassic. The majority of these finds have come from dense, cortical bone but recently have been discovered in cancellous bone. Since her initial discovery, Schweitzer has done a lot of work to verify that these microstructures are not biofilms, but instead are original organic tissue. This project was looking to get similar results to Schweitzer’s research and to find a simple test method for the initial ...


Iron Concretions In The Cretaceous Dakota Formation, Anthony Kohtz, Richard Kettler, David Loope 2016 University of Nebraska-Lincoln

Iron Concretions In The Cretaceous Dakota Formation, Anthony Kohtz, Richard Kettler, David Loope

UCARE Research Products

The Cretaceous Dakota Formation contains abundant iron oxide concretions. The precursors to the iron concretions are siderite (FeCO3) nodules that formed in a reducing floodplain environment. A variety of concretion morphologies formed when the precursor siderite nodules were dissolved by oxidizing groundwater in a paleoaquifer. Iron-oxidizing bacteria are able to oxidize aqueous Fe(II) to Fe(III) oxy-hydroxide at microaerophilic and neutrophilic conditions. This study investigated these concretions to determine if there was a microbial element in their formation and to characterize the concretion morphologies present in the Dakota. This is important for complete paleoenvironment interpretations and astrobiology pursuits.


Neogene Changes In Caribbean Paleoproductivity And The Diversity And Paleobiogeography Of Deep-Sea Benthic Foraminifera, Crystal Pletka 2016 Florida International University

Neogene Changes In Caribbean Paleoproductivity And The Diversity And Paleobiogeography Of Deep-Sea Benthic Foraminifera, Crystal Pletka

FIU Electronic Theses and Dissertations

The Neogene history of Caribbean deep-sea benthic foraminifera was investigated by calculating changes in paleoproductivity, diversity and paleobiogeography ~26 to 2 Ma, which includes the progressive closure of the Central American Seaway. Three hypotheses were tested: (1) Paleoproductivity values prior to closure of the Central American Seaway are similar in both the Caribbean and equatorial Pacific and then diverge by the time of early shoaling events; (2) Diversity values of benthic foraminifera prior to the closure of the Central American Seaway were similar in the Caribbean and EEP, and had changed by the time of early shoaling; and (3) during ...


Surface Scan Of The Parietal Fragment 2 Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Parietal Fragment 2 Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Parietal Fragment 1 Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Parietal Fragment 1 Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Premaxilla Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Premaxilla Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Dentary Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Dentary Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Squamosal Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Squamosal Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Scapula Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Scapula Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Femur Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Femur Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Surface Scan Of The Dorsal Vertebra Of Cpc 274, Brandon P. Hedrick 2016 University of Pennsylvania

Surface Scan Of The Dorsal Vertebra Of Cpc 274, Brandon P. Hedrick

VP3D Scans

CPC 274, a new centrosaurine specimen from Mexico, was unearthed in northern Coahuila from 2007-2011. The majority of elements that were found with CPC 274 were surface scanned using a Polhemus FastSCAN system in order to allow readers the ability to manipulate the bones in a 3D environment to assess features directly. The files are .obj files and can be visualized in MeshLabTM, which can be downloaded for free (MeshLab, Visual Computing Lab – ISTI – CNR http://meshlab.sourceforge.net/).


Multi-Proxy Reconstructions Of Holocene Environmental Change And Catchment Biogeochemistry Using Algal Pigments And Stable Isotopes Preserved In Lake Sediment From Baffin Island And Iceland, Christopher Roth Florian 2016 University of Colorado Boulder

Multi-Proxy Reconstructions Of Holocene Environmental Change And Catchment Biogeochemistry Using Algal Pigments And Stable Isotopes Preserved In Lake Sediment From Baffin Island And Iceland, Christopher Roth Florian

Geological Sciences Graduate Theses & Dissertations

Lake sediments provide a continuous record of environmental change, integrating information about multiple biogeochemical processes occurring within the lake and catchment. Much of this is recorded by the chemical characteristics of sedimentary organic matter, which can be used as a proxy for past conditions. This dissertation examines Holocene lake sediment records from Baffin Island and Iceland, which, as a result of Arctic amplification feedbacks, are particularly sensitive to changes in climate. We integrated sedimentary algal pigments with more commonly used proxies such as stable isotopes, C:N ratio, and biogenic silica in order to derive a more complete understanding of ...


Understanding Soft-Bodied Taphonomy: An Integrated Approach Incorporating Theoretical, Fossil, And Experimental Studies, Evan Pelzner Anderson 2016 University of Colorado Boulder

Understanding Soft-Bodied Taphonomy: An Integrated Approach Incorporating Theoretical, Fossil, And Experimental Studies, Evan Pelzner Anderson

Geological Sciences Graduate Theses & Dissertations

Non-biomineralized, or soft-bodied, fossils provide important paleontological information the “standard” shelly and bony fossil record cannot. Yet, a good understanding of soft-bodied taphonomy has proven elusive given the variety of histologies and preservation pathways that populate the soft-bodied fossil record. This dissertation addresses this problem using three separate but interconnected studies.

In the first study, a soft-bodied taphonomic model is synthesized by consulting the literature, with concentration on twelve soft-bodied deposits in the fossil record. This model groups soft-bodied preservation pathways into three classes based on how the microbial community effects preservation. Within each class, zones of consistent relationships between ...


Filling The Gaps: A Comprehensive Understanding Of Diets And Ecosystem Interactions Within The Modern And Fossil Small Mammal Communities Of Meade Basin, Kansas, Hannah Richardson, Kena Fox-Dobbs, Andrew Haveles 2016 University of Puget Sound

Filling The Gaps: A Comprehensive Understanding Of Diets And Ecosystem Interactions Within The Modern And Fossil Small Mammal Communities Of Meade Basin, Kansas, Hannah Richardson, Kena Fox-Dobbs, Andrew Haveles

Summer Research

The modern Great Plains ecosystem began shifting from a woodland biome to a grassland in the Miocene. Stable isotope analysis (SIA) of a diverse community of local consumers, in this case small mammals, provides both a paleoenvironmental record of the shift from woodland C3 biomass to grassland C4 biomass, and a paleoecological record of species interactions and community dynamics. The Meade Basin in southwestern Kansas contains a rich and fairly complete fossil record of a Great Plains small mammal community throughout the past 5 million years. SIA of fossil tooth enamel from Meade small mammals has revealed interesting ...


Micropaleontology And Isotope Stratigraphy Of The Upper Aptian To Lower Cenomanian (~114-98 Ma) In Odp Site 763, Exmouth Plateau, Nw Australia, Ali Alibrahim 2016 University of Massachusetts Amherst

Micropaleontology And Isotope Stratigraphy Of The Upper Aptian To Lower Cenomanian (~114-98 Ma) In Odp Site 763, Exmouth Plateau, Nw Australia, Ali Alibrahim

Masters Theses

The biostratigraphy and isotope stratigraphy of the upper Aptian to lower Cenomanian interval including oceanic anoxic events OAE1b, 1c and 1d are investigated in ODP Site 763, drilled on the Exmouth Plateau offshore northwest Australia. Benthic foraminifera suggest that Site 763 was situated in outer neritic to upper bathyal water depths (~150-600 m). OAEs of the Atlantic basin and Tethys are typically associated with organic carbon-rich black shales and δ13C excursions. However, OAEs at this high latitude site correlate with ocean acidification and/or pyrite formation under anoxic conditions rather than black shales. Ocean acidification maybe responsible for ...


Comparative Analysis Of Stromatolite Dome Spacing And Grazing Levels In The Lykins Formation Of Colorado And Southern Wyoming, Nicholas R. Warren 2016 University of Colorado, Boulder

Comparative Analysis Of Stromatolite Dome Spacing And Grazing Levels In The Lykins Formation Of Colorado And Southern Wyoming, Nicholas R. Warren

Undergraduate Honors Theses

Stromatolites are laminated structures that occur from the collection and binding of small grains of sediment by microorganisms. The appearance of stromatolites indicates a period of decreased grazing at a specific point in earth’s history. Stromatolites in the Lykins Formation of the Eastern slope of Colorado and Southern Wyoming flourished during the Permian-Triassic mass extinction event, which occurred approximately 250 million years ago (mya). This mass extinction event caused more than 90% of marine and terrestrial species to perish.

Due to their nature, the remains of the individual microbes that produced stromatolites are not preserved in the geologic record ...


Comparing Body Size Of The Sand Tiger Shark Striatolamia Macrota From Eocene Localities In The Eureka Sound Formation, Banks Island, Northern Canada, And The Tuscahoma Formation, Meridian, Mississippi, Dina M. Fieman 2016 University of Colorado, Boulder

Comparing Body Size Of The Sand Tiger Shark Striatolamia Macrota From Eocene Localities In The Eureka Sound Formation, Banks Island, Northern Canada, And The Tuscahoma Formation, Meridian, Mississippi, Dina M. Fieman

Undergraduate Honors Theses

As the most abundant vertebrate fossil in the geologic record, shark teeth have the potential to provide remarkable insight into the past. This is due to the added layer of enameloid in the teeth that make them exceptionally preservable. Among the most abundant fossil shark teeth discovered during the early to middle Eocene Epoch (55-50 Ma) belong to the sand tiger shark Striatolamia macrota. Two fossil localities, one from Banks Island, NWT, and the other known as the Red Hot Truck Stop in Meridian, Mississippi, contain a vast amount of Striatolamia macrota teeth. These two localities are of comparable age ...


Ocean Gateways And Glaciation: Planktic Foraminiferal Records From The Southern Ocean, Equatorial Pacific, And Caribbean, Andrew J. Fraass 2016 UMass

Ocean Gateways And Glaciation: Planktic Foraminiferal Records From The Southern Ocean, Equatorial Pacific, And Caribbean, Andrew J. Fraass

Doctoral Dissertations

Ocean gateway changes, once the best mechanism for driving abrupt climatic change, have fallen from favor. They have been largely replaced within the literature by changes in CO2 concentration and orbital forcing. This dissertation looks at three intervals of relative stability (Oligocene), prolonged change (Plio-Pleistocene), or transient events (Oligocene/Miocene boundary) in order to better understand the oceanographic circumstances which govern ‘events’ in the paleoceanographic record.

Chapter 1 discusses the chronostratigraphy of Integrated Ocean Drilling Program (IODP) Site U1396 (Expedition 340) in the Caribbean Sea. A combination of paleomagnetostratigraphy, biostratigraphy, astrochronology, and correlation to Marine Isotope Stages (MIS) allows ...


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