Paleobiology Commons^™

The Role Of Mites In The Construction And Weathering Of Siliceous Biospeleothems, María José López-Galindo

International Journal of Speleology

Acarines are well-documented as formative elements in the biocenosis of soils. However, their role in the construction and weathering of siliceous speleothems has received very little attention in previous research. The present study describes different groups of cavities (nesting/molting sites) excavated by these organisms in the surface of siliceous speleothems that are deposited in the fissures between various granite boulders in Southern Spain. There is evidence that there are immature stages that would survive the heat and drought of summer in the form of small larvae, or euedaphic nymphs, in the soil. This study provides the first description of how …

Are The Oxygen Isotope Values Of The Late Cretaceous Western Interior Seaway Different From The Open Ocean?, Camille H. Dwyer, Corinne Myers, Viorel Atudorei

Shared Knowledge Conference

The Western Interior Seaway (WIS) was a North American epicontinental sea that was connected to the open ocean through the passage of the northern Boreal Sea and the southern Tethys Sea from the early Albian (~113 million years ago) to the early Paleogene (~65 million years ago). The WIS began to recced and lost its connection to the southern Tethys Sea in the late Campanian (~72 million years ago). In the early Paleogene, the WIS dried up completely. The oxygen isotopic composition (δ18O) of benthic bivalves was measured from the upper Campanian and lower Maastrichtian (75 million years ago to …

Belowground Rhizomes In Paleosols: The Hidden Half Of An Early Devonian Vascular Plant, Jinzhuang Xue, Zhenzhen Deng, Pu Huang, Kangjun Huang, Michael J. Benton, Ying Cui

Ying Cui

The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant−soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils …

Modern And Paleoecological Perspectives On A Terrestrial-Marine Linkage In The Falkland Islands, Dulcinea V. Groff

Electronic Theses and Dissertations

The Falkland Islands are a biodiversity hotspot in the South Atlantic Ocean, with some of the world’s most important populations of seabirds and seals. The impact of climate change on these marine populations and their coastal breeding habitat in the Falklands is unknown. Coastal grasslands of Poa flabellata (tussac grass) form critical breeding habitat for wildlife, but have been heavily degraded by the introduction of livestock in the 17^th century. This dissertation investigates the impacts of global change (climate change, grazing) on P. flabellata and its sensitivity to the fecal nutrient subsidies provided by marine wildlife. Chapter 1 provides …

Global Deposits Of In Situ Upper Cambrian Microbialites: Implications For A Cohesive Model Of Origins, Ken P. Coulson

Proceedings of the International Conference on Creationism

The existence of in situ microbialites of biological origin located in upper Cambrian rocks in western Utah presents some problems for creationists as they seek to define the boundary that separates pre-Flood deposits from those that were deposited during the Flood event itself. These microbialites are extensive in nature, covering an area of at least 2600 km2, and are stacked one atop the other in multiple beds that span a thickness of at least 300 m, but could be as thick as several km (intercalated between wackestone wedges). Other microbialites found throughout similar upper Cambrian rocks in Nevada and California …

Historical Survey Of The Floating Mat Model For The Origin Of Carboniferous Coal Beds, Steven Arthur Austin, Roger W. Sanders

Proceedings of the International Conference on Creationism

For three hundred years geologists and paleobotanists have been attempting to describe the process that deposited plant material that formed Carboniferous coal beds. Autochthonous and allochthonous explanations in the early Nineteenth Century showed how scientific methodology becomes involved in coal interpretation. Autochthonous modelers used the paleobotany-strata-petrology-environment method to argue that coal is a terrestrial swamp deposit. Allochthonous modelers used the petrology-strata-paleobotany-environment method to describe coal as a subaqueous deposit. The two methodologies are best displayed at the end of the Nineteenth Century in the consensus autochthonists versus the French School allochthonists. Three depositional models have been offered for the origin …

Mainland Southeast Asia In The Longue Durée: A Zooarchaeological Test Of The "Broad Spectrum Revolution" In Northern Thailand, Cyler Norman Conrad

Anthropology ETDs

In northern Thailand, previous zooarchaeological research suggests that hunter-gatherers consumed a broad diversity of animal resources during the Pleistocene-Holocene transition and afterwards (Gorman 1971a). This is a pattern characteristic of Kent Flannery’s (1969) “broad spectrum revolution” hypothesis. Based primarily on presence and absence evidence, faunal assemblages in northern Thailand typically include species of mammals, reptiles, birds, fish and shellfish, suggesting that prehistoric foragers consumed a wide range of taxa within this mainland Southeast Asian tropical environment. Although zooarchaeological analyses commonly identify this pattern within prehistoric cave and rockshelter sites, past investigations have 1) not attempted to formally test Flannery’s hypothesis, …

The Carnivores Of Agate Fossil Beds National Monument: Miocene Dens And Waterhole In The Valley Of A Dryland Paleoriver, Robert M. Hunt Jr., Robert Skolnick, Joshua Kaufman

Zea E-Books Collection

In 1981 University of Nebraska paleontologists came upon an unexpected concentration of carnivore dens at Agate Fossil Beds National Monument in northwest Nebraska. The discovery of bones of Miocene beardogs, mustelids, and canids in their burrows was unparalleled and marked an exceptional event in the fossil record. Survey and excavation (1981–1990) established that six species of carnivores had, over time, occupied the dens with traces of their prey: juvenile and adult oreodonts, camels, and a neonatal rhinoceros. At least nine individuals of the wolf-like beardog Daphoenodon superbus, the most common carnivore, were identified from remains of young, mature, and aged …

Cretaceous Dinosaurs And The World They Lived In: A New Species Of Ornithischian Dinosaur From The Early Cretaceous (Aptian) Of Texas, Reconstruction Of The Brain Endocast And Inner Ear Of Malawisaurus Dixeyi, And Reconstruction Of The Paleoclimate And Paleoenvironment Of Cretaceous Terrestrial Formations In Texas And Oklahoma Using Pedogenic Minerals, Kate Andrzejewski

Earth Sciences Theses and Dissertations

Material from over thirty individuals of a new ornithopod was recovered from the Proctor Lake locality in the Twin Mountains Formation (Aptian) of north-central Texas. This material includes various ontogenetic stages, providing insight into the growth patterns of this species. The new ornithopod is recovered basal to Iguanodontia, but more derived than Hypsilophodon foxii. The presence and morphology of 4 premaxillary teeth along with a combination of both basal and derived characters distinguish this taxon from all other ornithopods.

A braincase of the Cretaceous titanosaurian sauropod Malawisaurus dixeyi was CT scanned and a 3D rendering of the endocast and inner …

Postcranial Morphology And The Locomotor Adaptations Of Extant And Extinct Crocodylomorphs And Lepidosaurs, Laura Rooney

Electronic Theses and Dissertations

I have collected a series of linear measurements of the postcranial skeletons of 43 extant crocodylian and lepidosaur taxa to determine if those engaging in similar locomotor behavior display similar morphology despite phylogenetic differences. Stepwise discriminant function analyses reveal reptile locomotor mode can be accurately predicted (over 80% correct) based on morphology. Semi-aquatic taxa are distinguished by a longer ischium relative to pubis length, a longer scapula relative to humerus length, and a broader acetabulum than terrestrial and arboreal taxa. Arboreal taxa display a more elongate, gracile humerus and a smaller acetabulum. This morphometric data can potentially be used to …

Body Size Downgrading Of Mammals Over The Late Quaternary, Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons, Jonathan L. Payne

School of Biological Sciences: Faculty Publications

Since the late Pleistocene, large-bodied mammals have been extirpated from much of Earth. Although all habitable continents once harbored giant mammals, the few remaining species are largely confined to Africa. This decline is coincident with the global expansion of hominins over the late Quaternary. Here, we quantify mammalian extinction selectivity, continental body size distributions, and taxonomic diversity over five time periods spanning the past 125,000 years and stretching approximately 200 years into the future. We demonstrate that size-selective extinction was already under way in the oldest interval and occurred on all continents, within all trophic modes, and across all time …

Paradigms And Paleoartists: How Our Perception Of Dinosaurs Forms, Jordan C. Oldham

The Research and Scholarship Symposium (2013-2019)

Thomas Kuhn in his famous work The Structure of Scientific Revolutions put forth his idea about how science changes. Kuhn thought that science changed by scientific revolutions brought on by an anomaly. After the anomaly, a crisis point would ensue as more scientists would research the anomaly. While in the process of research they would abandon the old paradigm in favor of one that would explain the anomaly. Not all anomalies create a crisis, but can rather result in a paradigm shift. These shifts occur within the old paradigm, and do not led to the formation of a new paradigm. …

Investigation Of Omnivorous Trophic Position In The Drilling Gastropod, Urosalpinx Cinerea, Using Stable Isotope Analysis, Molly E. Karnes, Michelle M. Casey

Scholars Week

Drill-holes found in the fossil record are an important tool to study ecological patterns of the past. It is therefore important to gain a better understanding of the role of extant drilling snails in modern ecosystems. Although traditionally considered a predator, trophic position of 3.0, specimens of the muricid Urosalpinx cinerea from Long Island Sound revealed trophic positions between 2.3 and 2.5, suggestive of an omnivorous diet. This study addresses the generality of this result by examining a U. cinerea population from Wilmington, North Carolina. Preliminary whole body, soft tissue stable isotope analysis of nitrogen and carbon was conducted on …

Redescription And Phylogenetic Analysis Of The Materials Assigned To The Taxon "Captorhinikos" Chozaensis, Jason Paul Jung

Electronic Theses, Projects, and Dissertations

“Captorhinikos” chozaensis is a multiple-tooth-rowed captorhinid reptile from the Lower Permian Clear Fork Group, undivided formation. Upon re-examination of the materials associated with the species from both the Chicago Field Museum of Natural History, and the Smithsonian United States National Museum, I reaffirm their affinity and collective identity as a valid taxon. “Captorhinikos” chozaensis does not, however, belong with either of the two members of its genus, C. valensis or “C.” parvus, instead occupying its own branch on the phylogenetic tree of the Captorhinidae. This conclusion is based in strong results from a combined phylogenetic parsimony analysis combined with …

Stratigraphy Of The Upper Silurian To Middle Devonian, Southwestern Ontario, Shuo Sun

Electronic Thesis and Dissertation Repository

The upper Silurian–Middle Devonian succession was dominated by carbonate and evaporite deposits, with minor siliciclastic sedimentation, and a significant hiatus across the Siluro-Devonian (S-D) boundary in southwestern Ontario. The stratigraphic units include, in ascending order: Late Silurian Bass Islands/Bertie formations and Salina G Unit, the Devonian Oriskany Formation, Bois Blanc Formation (including Springvale Member), Detroit River Group (including the Lucas, Amherstburg and Sylvania formations), Onondaga Formation, and Dundee Formation.

Below the S-D unconformity, the upper Silurian Bass Islands/Bertie formations are predominantly dolostone of peritidal-sabkha origin and episodic subaerial exposure. Revised stratigraphic correlation shows that the Bertie Formation is older than …

Examining The Use Of Amazon’S Mechanical Turk For Edge Extraction Of The Occlusal Surface Of Fossilized Bovid Teeth, George K. Thiruvathukal, Gregory J. Matthews, Maxwell P. Luetkemeier, Juliet K. Brophy

George K. Thiruvathukal

In order to reconstruct environments associated with Plio-Pleistocene hominins in southern Africa, researchers frequently rely upon the animals associated with the hominins, in particular, animals in the Family Bovidae. Bovids in southern Africa are typically identified by their teeth. However, identifying the taxon of a bovid tooth is challenging due to various biasing factors. Furthermore, inaccurate identification of fossil bovids can have significant consequences on the reconstructed paleoenvironment. Recent research on the classification of bovid fossil teeth has relied on using elliptical Fourier analysis to summarize the shape of the outline of the occlusal surface of the tooth and the …

Nitrogen Isotopes Suggest A Change In Nitrogen Dynamics Between The Late Pleistocene And Modern Time In Yukon, Canada, Farnoush Tahmasebi, Fred J. Longstaffe, Grant Zazula

Earth Sciences Publications

A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ¹³C and δ¹⁵N for vegetation and bone …

A Quantitative Analysis Of Intermediate Forms Within Astarte From The Atlantic Coastal Plain, Philip Roberson

Murray State Theses and Dissertations

The Atlantic Coastal Plain has long been recognized as a natural laboratory useful for testing hypotheses about various environmental and ecological effects on marine fauna. For studies such as these to continue being conducted in a rigorous and easily repeatable manner, a reliable taxonomy must be established for genera within this physiographic province. The bivalve genus, Astarte, is a cosmopolitan genus that is commonly found within the Atlantic Coastal Plain. This genus has many formally recognized species, even though it lacks many features that would encourage diversification, marking it as a taxonomic group in need of potential revision. The …

Two Post-Glacial Sagebrush Steppe Fire Records At The Wildland-Urban Interface, Eastern Cascades, Washington, Dusty Pilkington

All Master's Theses

Recent increases in large fires in the rapidly developing wildland-urban interface (WUI) areas of central Washington, where development intermixes with wildland fuels, contribute to federal firefighting costs exceeding of $1 billion annually. In addition, cheatgrass (Bromus tectorum) invasion and anthropogenic-caused warming shorten fire return intervals while lengthening fire seasons. These climatic, ecological, economic, and social factors combine with fuel accumulation resulting from historic fire suppression to threaten lives and property in the WUI. To plan for safe growth in WUI areas, long-term fire histories are needed to expand understanding of past fire regimes in an understudied ecosystem, sagebrush …

Volcanogenic Pseudo-Fossils From The ~3.48 Ga Dresser Formation, Pilbara, Western Australia, David Wacey, Nora Noffke, Martin Saunders, Paul Guagliardo, David M. Pyle

OES Faculty Publications

The ~ 3.48 billion-year-old Dresser Formation, Pilbara Craton, Western Australia, is a key geological unit for the study of Earth's earliest life and the habitats it occupied. Here, we describe a new suite of spheroidal to lenticular microstructures that morphologically resemble some previously reported Archean microfossils. Correlative microscopy shows that these objects have a size distribution, wall ultrastructure, and chemistry that are incompatible with a microfossil origin and instead are interpreted as pyritized and silicified fragments of vesicular volcanic glass. Organic kerogenous material is associated with much of the altered volcanic glass; variable quantities of organic carbon line or fill …