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Articles 181 - 210 of 394

Full-Text Articles in Paleobiology

Short- And Long-Term Trends In Ecological Interactions: From Predator-Prey Interactions To Phanerozoic Diversification, Subhronil Mondal Nov 2014

Short- And Long-Term Trends In Ecological Interactions: From Predator-Prey Interactions To Phanerozoic Diversification, Subhronil Mondal

USF Tampa Graduate Theses and Dissertations

During the last two decades, a broad spectrum of short- and long-term studies on different taxonomic groups has enriched our understanding about how dynamics of taxonomic and ecological diversification have changed through geologic time. There are two major issues that have impacted these studies: the quality and quantity of data used are often insufficient in various ways and the methods used may produce results that are more equivocal than supposed. To investigate these issues more fully, this dissertation focuses on studies on two major aspects: 1) short-term studies examining the nature of successful and unsuccessful predatory attacks on Plio-Pleistocene bivalves; …


Aptian To Santonian Foraminiferal Biostratigraphy And Paleoenvironmental Change In The Sverdrup Basin As Revealed At Glacier Fiord, Axel Heiberg Island, Canadian Arctic Archipelago, Claudia J. Schröder-Adams, Jens O. Herrle, Ashton F. Embry, James W. Haggart, Jennifer M. Galloway, Adam T. Pugh, David M. Harwood Nov 2014

Aptian To Santonian Foraminiferal Biostratigraphy And Paleoenvironmental Change In The Sverdrup Basin As Revealed At Glacier Fiord, Axel Heiberg Island, Canadian Arctic Archipelago, Claudia J. Schröder-Adams, Jens O. Herrle, Ashton F. Embry, James W. Haggart, Jennifer M. Galloway, Adam T. Pugh, David M. Harwood

ANDRILL Research and Publications

Exceptional exposures of a High Arctic Cretaceous sedimentary record were studied at Glacier Fiord, Axel Heiberg Island. The succession reveals a complex Aptian to Santonian paleoenvironmental history of the Sverdrup Basin that documents several global events. Foraminiferal faunas in combination with rare macrofossil occurrences permit the distinction of nine zones that facilitate biostratigraphic correlations to other High Arctic locales, the Beaufort Mackenzie Basin and the Western Interior Sea. The depositional environment as exposed in the Christopher, Hassel, Bastion Ridge and Kanguk formations changed frequently from a shelf to a shoreface setting. Most sequence boundaries appear to be conformable where shoaling …


Discovery Of A 240 Million Year Old Nematode Parasite Egg In A Cynodont Coprolite Sheds Light On The Early Origin Of Pinworms In Vertebrates, Jean-Pierre Hugot, Scott Gardner, Victor Borba, Priscilla Araujo, Daniela Leles, Átila Da-Rosa, Juliana Dutra, Luis Fernando Ferreira, Adauto Araújo Nov 2014

Discovery Of A 240 Million Year Old Nematode Parasite Egg In A Cynodont Coprolite Sheds Light On The Early Origin Of Pinworms In Vertebrates, Jean-Pierre Hugot, Scott Gardner, Victor Borba, Priscilla Araujo, Daniela Leles, Átila Da-Rosa, Juliana Dutra, Luis Fernando Ferreira, Adauto Araújo

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Background: We report the discovery of a nematode parasite egg (Nemata: Oxyurida) from a coprolite closely associated with the remains of several species of Cynodontia, dated to 240 million years old. This finding is particularly significant because this is the oldest record of an oxyurid nematode yet discovered, and because the cynodonts are considered a stem-group of the mammals.

Methods: We extracted material from a fully mineralized coprolite by both scraping the surface, and removing fragments from its interior with clean dental instruments used a single time. A single drop of glycerol from a new vial was added as a …


Laurentian Great Lakes Phytoplankton And Their Water Quality Characteristics, Including A Diatom-Based Model For Paleoreconstruction Of Phosphorus, Euan D. Reavie, Adam J. Heathcote, Victoria L. Shaw Chraïbi Aug 2014

Laurentian Great Lakes Phytoplankton And Their Water Quality Characteristics, Including A Diatom-Based Model For Paleoreconstruction Of Phosphorus, Euan D. Reavie, Adam J. Heathcote, Victoria L. Shaw Chraïbi

Department of Earth and Atmospheric Sciences: Faculty Publications

Recent shifts in water quality and food web characteristics driven by anthropogenic impacts on the Laurentian Great Lakes warranted an examination of pelagic primary producers as tracers of environmental change. The distributions of the 263 common phytoplankton taxa were related to water quality variables to determine taxon-specific responses that may be useful in indicator models. A detailed checklist of taxa and their environmental optima are provided. Multivariate analyses indicated a strong relationship between total phosphorus (TP) and patterns in the diatom assemblages across the Great Lakes. Of the 118 common diatom taxa, 90 (76%) had a directional response along the …


Time, Money, And Melting Ice: Proposal For A Coopertive Study Of The World’S Cave Ice In A Race Against Climate Change, George Veni, Lewis Land, Aurel Perşoiu Aug 2014

Time, Money, And Melting Ice: Proposal For A Coopertive Study Of The World’S Cave Ice In A Race Against Climate Change, George Veni, Lewis Land, Aurel Perşoiu

The International Workshop on Ice Caves

Climate change is a global phenomenon that is melting and threatening to melt ice deposits in many of the world’s ice caves. The National Cave and Karst Research Institute of the USA is concerned that major and important paleoclimate and paleoenvironmental records stored in cave ice will soon be lost, and is proposing an international collaborative effort to overcome funding and logistical challenges to sample and analyze at least a representative collection of ice from several regions before further melting occurs.


Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston Aug 2014

Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston

The International Workshop on Ice Caves

Potential mechanisms for creating cavities in icy extraterrestrial bodies have been tentatively explored by several authors. On one hand we have examples of mechanisms that create caves in water ice here on Earth. In addition, there may be unique mechanisms on other Solar System objects that do not occur on Earth but might produce cavities, e.g. sublimation of comets upon perihelion passage. The methods of detecting such cavities depend upon the nature of the icy body in question, the potential for orbital or landed missions to visit those bodies in the future, and remote or landed methods for detecting the …


Tempo And Mode Of Domestication During The Neolithic Revolution: Evidence From Dental Mesowear And Microwear Of Sheep, Melissa Zolnierz Aug 2014

Tempo And Mode Of Domestication During The Neolithic Revolution: Evidence From Dental Mesowear And Microwear Of Sheep, Melissa Zolnierz

Graduate Theses and Dissertations

The Neolithic Revolution marked a dramatic change in human subsistence practices. In order to explain this change, we must understand the motive forces behind it. Researchers have proposed many different stimuli, with most theories invoking environmental dynamics, human population density increases beyond environmental carrying capacity, and the natural outgrowth of human and plant/animal interactions. However, unanswered questions remain concerning the mechanics of animal domestication. Traditional studies of changing faunal morphology and skeletal population profiles offer some clues, but such research has had limited success identifying stages intermediate between wild and domesticated forms, which makes it difficult to discern initial attempts …


New Insights Into Skeletal Morphology Of The Oldest Known Silicoflagellates : Variramus, Cornua And Gleserocha Gen. Nov. = Nouvelles Connaissances Sur La Morphologie Du Squelette Des Plus Anciennes Silicoflagellés Connus : Variramus, Cornua Et Gleserocha Gen. Nov., Kevin Mccartney, Jakub Witkowski, David M. Harwood Jun 2014

New Insights Into Skeletal Morphology Of The Oldest Known Silicoflagellates : Variramus, Cornua And Gleserocha Gen. Nov. = Nouvelles Connaissances Sur La Morphologie Du Squelette Des Plus Anciennes Silicoflagellés Connus : Variramus, Cornua Et Gleserocha Gen. Nov., Kevin Mccartney, Jakub Witkowski, David M. Harwood

ANDRILL Research and Publications

Two of the oldest known silicoflagellate-bearing sediments, lower Albian at Ocean Drilling Program Site 693 in the Weddell Sea of Antarctica and Santonian in the Devon Island sequence of the Canadian Archipelago, are re-examined with a focus on silicoflagellate genera Variramus, Cornua, and Gleserocha that lack basal rings, a feature appearing during late Santonian/early Campanian time within the genus Corbisema. The extraordinary variability of Variramus aculeifera is studied, and a new genus Gleserocha is proposed for taxa with apical structures made of three struts, but without pikes. This new genus includes previously described Variramus wisei and Cornua …


The Evolution Of Respiratory O2/No Reductases: An Out-Of-The-Phylogenetic-Box Perspective, Anne-Lise Ducluzeau, Barbara Schoepp-Cothenet, Robert Van Lis, Frauke Baymann, Michael J. Russell, Wilfgang Nitschke Jun 2014

The Evolution Of Respiratory O2/No Reductases: An Out-Of-The-Phylogenetic-Box Perspective, Anne-Lise Ducluzeau, Barbara Schoepp-Cothenet, Robert Van Lis, Frauke Baymann, Michael J. Russell, Wilfgang Nitschke

Department of Biochemistry: Faculty Publications

Complex life on our planet crucially depends on strong redox disequilibria afforded by the almost ubiquitous presence of highly oxidizing molecular oxygen. However, the history of O2-levels in the atmosphere is complex and prior to the Great Oxidation Event some 2.3 billion years ago, the amount of O2 in the biosphere is considered to have been extremely low as compared with present-day values. Therefore the evolutionary histories of life and of O2-levels are likely intricately intertwined. The obvious biological proxy for inferring the impact of changing O2-levels on life is the evolutionary history …


Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin May 2014

Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin

Electronic Theses and Dissertations

Bison spp. (bison) fossils are scarce on the Colorado Plateau, especially within the greater Grand Canyon region. Because of the poor fossil record for bison on the plateau and in Grand Canyon National Park, various resource managers have surreptitiously designated bison a nonnative and human-introduced species. The lack of evidence for bison seems to be the result of collection bias rather than a true lack of bison remains. Today, Grand Canyon National Park has a neighboring herd of 350 bison that have meandered unwantedly onto National Park lands from neighboring Forest Service and State of Arizona lands. This study spatiotemporally …


Palaeomagnetic And Synchrotron Analysis Of >1.95 Ma Fossil-Bearing Palaeokarst At Haasgat, South Africa, Andy I R Herries, Peter Kappen, Anthony D T Kegley, David Patterson, Daryl L. Howard, Martin D. De Jonge, Stephany Potze, Justin W. Adams Mar 2014

Palaeomagnetic And Synchrotron Analysis Of >1.95 Ma Fossil-Bearing Palaeokarst At Haasgat, South Africa, Andy I R Herries, Peter Kappen, Anthony D T Kegley, David Patterson, Daryl L. Howard, Martin D. De Jonge, Stephany Potze, Justin W. Adams

Peer Reviewed Articles

Palaeomagnetic analysis indicates that Haasgat, a fossil-bearing palaeocave in the Gauteng Province of South Africa, is dominated by reversed magnetic polarity in its oldest, deepest layers and normal polarity in the younger layers. The presence of in-situ Equus specimens suggests an age of less than ~2.3 Ma, while morphological analysis of faunal specimens from the ex-situ assemblage suggests an age greater than 1.8 Ma. Given this faunal age constraint, the older reversed polarity sections most likely date to the beginning of the Matuyama Chron (2.58–1.95 Ma), while the younger normal polarity deposits likely date to the very beginning of the …


Influence Of Introgression And Geological Processes On Phylogenetic Relationships Of Western North American Mountain Suckers (Pantosteus, Catostomidae), Peter J. Unmack, Thomas E. Dowling, Nina J. Laitinen, Carol L. Secor, Richard L. Mayden, Dennis K. Shiozawa, Gerald R. Smith Mar 2014

Influence Of Introgression And Geological Processes On Phylogenetic Relationships Of Western North American Mountain Suckers (Pantosteus, Catostomidae), Peter J. Unmack, Thomas E. Dowling, Nina J. Laitinen, Carol L. Secor, Richard L. Mayden, Dennis K. Shiozawa, Gerald R. Smith

Biological Sciences Faculty Research Publications

Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data …


Rapid Fluctuations In Mid-Latitude Siliceous Plankton Production During The Middle Eocene Climatic Optimum (Odp Site 1051, Western North Atlantic), Jakub Witkowski, Steven M. Bohaty, Kirsty M. Edgar, David M. Harwood Jan 2014

Rapid Fluctuations In Mid-Latitude Siliceous Plankton Production During The Middle Eocene Climatic Optimum (Odp Site 1051, Western North Atlantic), Jakub Witkowski, Steven M. Bohaty, Kirsty M. Edgar, David M. Harwood

ANDRILL Research and Publications

The Middle Eocene Climatic Optimum (MECO; ~ 40 million years ago [Ma]) is one of the most prominent transient global warming events in the Paleogene. Although the event is well documented in geochemical and isotopic proxy records at many locations, the marine biotic response to the MECO remains poorly constrained. We present new high-resolution, quantitative records of siliceous microplankton assemblages from the MECO interval of Ocean Drilling Program (ODP) Site 1051 in the subtropical western North Atlantic Ocean, which are interpreted in the context of published foraminiferal and bulk carbonate stable isotope (δ18O and δ13C) records. …


Evolution Of The Freshwater Sardinella, Sardinella Tawilis (Clupeiformes: Clupeidae), In Taal Lake, Philippines And Identification Of Iits Marine Sister-Species, Sardinella Hualiensis, Demian Willette, Kent E. Carpenter, Mudjekeewis Santos Jan 2014

Evolution Of The Freshwater Sardinella, Sardinella Tawilis (Clupeiformes: Clupeidae), In Taal Lake, Philippines And Identification Of Iits Marine Sister-Species, Sardinella Hualiensis, Demian Willette, Kent E. Carpenter, Mudjekeewis Santos

Biological Sciences Faculty Publications

We identify the sister species of the world's only freshwater sardinella, Sardinella tawilis (Herre, 1927) of Taal Lake, Philippines as the morphologically-similar marine Taiwanese sardinella Sardinella hualiensis (Chu and Tsai, 1958). Evidence of incomplete lineage sorting and a species tree derived from three mitochondrial genes and one nuclear gene indicate that S. tawilis diverged from S. hualiensis in the late Pleistocene. Neutrality tests, mismatch distribution analysis, sequence diversity indices, and species tree analysis indicate populations of both species have long been stable and that the divergence between these two lineages occurred prior to the putative 18th century formation of Taal …


Analysis Of A Sponge Bioherm From The Hermosa Group, Molas Lake Area, Colorado, Joanna Hamilton Jan 2014

Analysis Of A Sponge Bioherm From The Hermosa Group, Molas Lake Area, Colorado, Joanna Hamilton

Honors Projects

The Hermosa Group is a Pennsylvanian (~310 Ma) rock package found in the southwestern San Juan Mountains and the Paradox Basin. The Paradox Basin was an evaporite basin in which alternating carbonate, sandstone and siltstone layers were deposited at the margins. Within the carbonate layers, ancient phylloid algal mounds and sponge bioherms can be found. In this project I document fossil sponges and algae from a Hermosa Group locality in southwestern Colorado. I look at the environments in which the sponges lived, those being relatively deep water, above wave-base; as well as inter-sponge growth habits, where one is dominant and …


Low Resolution Examination Of Cool-Water Carbonate Foraminifera Around Tasmania During The Pleistocene, Sara Jane Hughes Jan 2014

Low Resolution Examination Of Cool-Water Carbonate Foraminifera Around Tasmania During The Pleistocene, Sara Jane Hughes

Masters Theses

Benthic foraminifera from nine sediment samples recovered during Ocean Drilling Program (ODP) Leg 189: The Tasman Gateway were examined to determine how changing Southern Ocean conditions affect benthic foraminiferal populations. All samples come from Site 1168 situated 70km from the coast of Tasmania on the western continental slope (2463 m below the surface) and are spaced at roughly 150,000 years apart. Identifications of benthic foraminifera were done with a dissecting microscope and several reference books. Foraminifera were correlated with environmental proxy data obtained from Brughmans (2003) (total organic carbon, carbonate, siliciclastics, coarse fractions, chlorin, barium, aluminum, iron, and titanium) and …


Patterns Of Maximum Body Size Evolution In Cenozoic Land Mammals: Eco-Evolutionary Processes And Abiotic Forcing, Juha J. Saarinen, Alison G. Boyer, James H. Brown, Daniel P. Costa, S.K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L. Gittleman, Marcus J. Hamilton, Larisa E, Harding, Kari Lintulaakso, S. Kathleen Lyons, Jordan G. Okie, Richard M. Sibly, Patrick R. Stephens, Jessica Theodor, Mark D. Uhen, Felisa A. Smith Jan 2014

Patterns Of Maximum Body Size Evolution In Cenozoic Land Mammals: Eco-Evolutionary Processes And Abiotic Forcing, Juha J. Saarinen, Alison G. Boyer, James H. Brown, Daniel P. Costa, S.K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L. Gittleman, Marcus J. Hamilton, Larisa E, Harding, Kari Lintulaakso, S. Kathleen Lyons, Jordan G. Okie, Richard M. Sibly, Patrick R. Stephens, Jessica Theodor, Mark D. Uhen, Felisa A. Smith

School of Biological Sciences: Faculty Publications

There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at …


Upper Pleistocene And Holocene Palaeoenvironmental Records In Cueva Mayor Karst (Atapuerca, Spain) From Different Proxies: Speleothem Crystal Fabrics, Palynology And Archaeology., Virginia Martínez-Pillado, Arantza Aranburu, Juan Luis Arsuaga, Blanca Ruiz-Zapata, Maria José Gil-García, Heather Stoll, Iñaki Yusta, Eneko Iriarte, José Miguel Carretero, R. Lawrence Edwards, Hai Cheng Jan 2014

Upper Pleistocene And Holocene Palaeoenvironmental Records In Cueva Mayor Karst (Atapuerca, Spain) From Different Proxies: Speleothem Crystal Fabrics, Palynology And Archaeology., Virginia Martínez-Pillado, Arantza Aranburu, Juan Luis Arsuaga, Blanca Ruiz-Zapata, Maria José Gil-García, Heather Stoll, Iñaki Yusta, Eneko Iriarte, José Miguel Carretero, R. Lawrence Edwards, Hai Cheng

International Journal of Speleology

The Cueva Mayor karst system of Atapuerca, in Northern Spain, hosts a highly significant record of human occupation from the Pleistocene. The climatic context of the human activities during the Pleistocene-Holocene for this inland site has not been well constrained, since existing records of the palaeoclimatic evolution of the Northern Iberian Peninsula are from more distal coastal and high-elevation sites. In this study, we interpret the palaeoenvironmental information recorded on the petrography of a stalagmite and the pollen spectra of the Sierra de Atapuerca karst system during the last 20 kyr. The integration of both types of records has allowed …


Ichnology And Paleoecology Of The Jurassic Aztec Sandstone, Heather Marie Stoller Dec 2013

Ichnology And Paleoecology Of The Jurassic Aztec Sandstone, Heather Marie Stoller

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study I describe and interpret tracks and trackways of the Jurassic Aztec Sandstone of southern Nevada and southern California. This study involved mapping of all known tracks and trackways, including foot length, stride length, and trackway width. Photogrammetric data, collected by Bureau of Land Management scientists, were utilized for several trackways in Red Rock Canyon National Conservation Area.

More than three hundred tracks belonging to five ichnotaxa were documented within the Aztec Sandstone, including about 165 tridactylGrallator, 250 tetradactyl (four-toed)Brasilichniumtracks, and 7 arthropod trackways ofOctopodichnusandPaleohelcura. Four of the five ichnotaxa were not previously reported from the Aztec Sandstone. …


Postglacial Faunal Records From Cave Deposits In Jasper National Park, Alberta, Canada, Christopher N. Jass, Greg Horne, Dave Critchley Nov 2013

Postglacial Faunal Records From Cave Deposits In Jasper National Park, Alberta, Canada, Christopher N. Jass, Greg Horne, Dave Critchley

National Cave and Karst Management Symposium 2013

In 2009, we initiated an on-going, long term research project that focuses on exploration of fossil-bearing cave deposits in Jasper National Park. Specifically, we were interested in understanding patterns of mammalian re-colonization of mountainous regions following late Pleistocene deglaciation. Our work has focused on the identification of fossil-bearing cave deposits, excavation and sampling of those deposits, and radiocarbon dating of recovered remains. Examined sites have at least an age of 9600 years BP. Research at four cave sites, located in relatively close proximity to one another, is contributing to an improved understanding of the late Quaternary record of Jasper National …


Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova Aug 2013

Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova

Boise State University Theses and Dissertations

The continuous Pennsylvanian shallow-marine, paralic, siliciclastic succession in the Donets Basin is pivotal for correlation of marine and continental strata in northern Pangaea with coeval shallow-marine mainly carbonate strata in the Moscow Basin, a historical type area of Moscovian Horizons. The details of the history of establishment, lithostratigraphy and current biostratigraphy of Podolskian and Myachkovian Horizons in the Moscow Basin that are not readily available in Western literature are reviewed.

A model of cyclic recurrence (~0.6 —1myr) of three main fusulinid assemblages in the Pennsylvanian siliciclastic-carbonate succession in the Donets Basin is proposed. A Hemifusulina-association (A) indicates the onset …


Paleoecology Of Late Pleistocene Megaherbivores: Stable Isotope Reconstruction Of Environment, Climate, And Response, Aubrey Mae Bonde Aug 2013

Paleoecology Of Late Pleistocene Megaherbivores: Stable Isotope Reconstruction Of Environment, Climate, And Response, Aubrey Mae Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Late Pleistocene megaherbivore communities of the Pacific and Mountain West states of California and Nevada are under-analyzed in regard to ecological function (diet, mobility, niche partitioning, and range of ecological tolerance). Stable isotope analysis is a powerful tool that is known to recover primary paleodiet and paleoenvironmental information from biogenic materials, such as enamel and dentin. This dissertation explores the use of carbon and oxygen stable isotopes in Late Pleistocene (40-10 Ka) megaherbivore teeth to gain a better understanding of inter- and intra-specific behavior and reconstruct Late Pleistocene ecosystems of California and Nevada. Radiocarbon dates exist for most of the …


Analysis Of The Blancan Procyonids Of Florida, Laura S. Gilmore May 2013

Analysis Of The Blancan Procyonids Of Florida, Laura S. Gilmore

Electronic Theses and Dissertations

Procyonids are well known biologically but knowledge of their fossil record is comparatively sparse. This study seeks to describe a sample of late Blancan procyonid fossils composed mostly of postcranial and dental material. Fossils are analyzed using linear and 2D geometric morphometrics and compared with a large sample of modern specimens from a wide geographic area to understand the range of intraspecific variation. The large Procyon species is described as a new taxon based on morphology of the postcrania and lower dentition, while another Procyon species is also described as new due to an apomorphy in the upper dentition. A …


A New Species Of Teleoceras From The Late Miocene Gray Fossil Site, With Comparisons To Other North American Hemphillian Species, Rachel A. Short May 2013

A New Species Of Teleoceras From The Late Miocene Gray Fossil Site, With Comparisons To Other North American Hemphillian Species, Rachel A. Short

Electronic Theses and Dissertations

A thorough morphological description of Teleoceras material from the Gray Fossil Site, Gray, Tennessee is provided. This is the only record of a browsing Teleoceras and, as a late Hemphillian locality, represents one of the youngest populations. Linear measurements of post-cranial elements indicate proportional differences between Teleoceras from the Gray Fossil Site and those from other Hemphillian localities. These differences are more pronounced in the elements of the forelimb than in those of the hind limb. Statistical analyses of post-cranial elements from 3 Hemphillian species of Teleoceras suggest that these differences should not be used to separate species. However, the …


Paleoecology Of Nebraska’S Ungulates During The Eocene–Oligocene Climate Transition, Grant S. Boardman Apr 2013

Paleoecology Of Nebraska’S Ungulates During The Eocene–Oligocene Climate Transition, Grant S. Boardman

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

The White River Group (WRG) preserves the Eocene-Oligocene climate transition (EOCT), an interval of global cooling and drying during the onset of Antarctic glaciation. In the Great Plains, a shift from forested conditions to drier woodland-savanna biomes is hypothesized to have occurred at this time. I test this hypothesis through the analyses of several paleoenvironmental proxies on the teeth of 12 WRG ungulate species: stable carbon and oxygen isotopes from tooth enamel, and mesowear and microwear texture. The EOCT shift toward more open habitats and lower vegetation density under drying climates should have resulted in an increase in mean carbon …


Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn Jan 2013

Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn

ANDRILL Research and Publications

The AND-1B drill core (1285 m-long) was recovered, inside the ANDRILL (ANtarctic geological DRILLing) Program, during the austral summer of 2006/07 from beneath the floating McMurdo Ice Shelf. Drilling recovered a stratigraphic succession of alternating diamictites, diatomites and volcaniclastic sediments spanning about the last 14 Ma. A core portion between 350 and 480 mbsf, including a 80 m-thick diatomite interval recording the early Pliocene warming event, was investigated in term of opal biogenic content and element geochemistry. Across the diatomite interval, in spite of the lithological uniformity, a fluctuating biogenic opal profile mirrors the δ18O record, testifying a decrease in …


Microbially Induced Sedimentary Structures Recording An Ancient Ecosystem In The Ca. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia, Nora Noffke, Daniel Christian, David Wacey, Robert M. Hazen Jan 2013

Microbially Induced Sedimentary Structures Recording An Ancient Ecosystem In The Ca. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia, Nora Noffke, Daniel Christian, David Wacey, Robert M. Hazen

OES Faculty Publications

Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 billion years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to …


Impact Of Pre-Columbian Agriculture, Climate Change, And Tectonic Activity Inferred From A 5,700-Year Paleolimnological Record From Lake Nicaragua, Jennifer E. Slate, Thomas C. Johnson, Ted C. Moore Jan 2013

Impact Of Pre-Columbian Agriculture, Climate Change, And Tectonic Activity Inferred From A 5,700-Year Paleolimnological Record From Lake Nicaragua, Jennifer E. Slate, Thomas C. Johnson, Ted C. Moore

Biology Faculty Publications

Lake Nicaragua, the largest lake in Central America, is a promising site for paleolimnological study of past climate change, tectonic and volcanic activity, and pre-Columbian agriculture in the region. It is near the northern limit of the Intertropical Convergence Zone (ITCZ), which brings the rainy season to the tropics, so effects of decreasing precipitation due to southern migration of the ITCZ through the Holocene should be observable. Because fault zones and an active volcano lie within the lake, the long-term impact of tectonic and volcanic activity can also be examined. Finally, the fertile volcanic soils near the lake may have …


A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur Jan 2013

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Antioch University Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …


Cursorial Adaptations In The Forelimb Of The Giant Short-Faced Bear, Arctodus Simus, Revealed By Traditional And 3d Landmark Morphometrics, Eric Randally Lynch Aug 2012

Cursorial Adaptations In The Forelimb Of The Giant Short-Faced Bear, Arctodus Simus, Revealed By Traditional And 3d Landmark Morphometrics, Eric Randally Lynch

Electronic Theses and Dissertations

The paleobiology of the Pleistocene North American giant short-faced bear, Arctodus simus, has eluded paleontologists for decades. Its more gracile form has led past researchers to myriad intepretations of the locomotion and feeding ecology of this species. While earlier studies have focused on craniodental morphology and simple postcranial indices, it is forelimb morphology that represents a direct compromise between locomotor and foraging behavior. The study here uses traditional and 3D landmark morphometrics to more completely compare the 3-dimensional shape of the major forelimb elements and their muscle attachment sites between A. simus, extant ursids, and other carnivorans. Results …