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Articles 1 - 6 of 6
Full-Text Articles in Paleobiology
Testing The Niche Center Hypothesis In The Fossil Record Of Atlantic Bivalves, Rhiannon Z. Nolan
Testing The Niche Center Hypothesis In The Fossil Record Of Atlantic Bivalves, Rhiannon Z. Nolan
Earth and Planetary Sciences ETDs
Paleoecological analyses of six shallow marine bivalves were conducted to test the Abundant Center Hypothesis using data from the fossil record of the Pleistocene through modern day. This hypothesis predicts the highest abundance of a species is at the center of the geographic or environmental range, decreasing toward the edges. In geographic space, distances to a centerline within a geographic range were variably correlated with population abundances, and some species displayed a sharp drop-off in abundance as distance increased. In environmental space, bivalve species showed moderate correlations between abundance and centrality when measured using cumulative data across the last 2.8 …
Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid
Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …
Niche Dynamics Of The Felid Guild Following The Pleistocene Megafaunal Extinction, Nicholas A. Freymueller
Niche Dynamics Of The Felid Guild Following The Pleistocene Megafaunal Extinction, Nicholas A. Freymueller
Biology ETDs
The loss of large carnivores is fundamentally restructuring modern mammal communities. However, large carnivore removal is not exclusively a modern trend. The Pleistocene Megafaunal Extinction (PME) resulted in a near-eradication of hyper-carnivorous felids such as saber-toothed cats. However, it is unclear if smaller surviving meso-felids began to infill this ecological vacuum post-PME. I apply Ecological Niche Modeling (ENM) to test evaluate whether surviving felids filled in vacant niches post-extinction, and hypothesize that they ought to have shown increased niche-overlap patterns with mega-felids post-extinction. I model species’ fundamental niches using a multi-temporal approach, and develop a novel test to model realized …
A Tale Of Two Species: Black-Tailed And White-Tailed Prairie Dog Biogeography From The Last Interglacial To 2070, April Dawn Bledsoe
A Tale Of Two Species: Black-Tailed And White-Tailed Prairie Dog Biogeography From The Last Interglacial To 2070, April Dawn Bledsoe
Electronic Theses and Dissertations
Ecological niche models (ENMs) were created for White-tailed and Black-tailed prairie dogs and projected into the Last Interglacial (LI), the Last Glacial Maximum (LGM), and mid-Holocene (mid-H) to discern possible past suitable habitat for both species. Additionally, ENMs were projected into the future year 2070 representative concentration pathways (RCPs) 2.6 and 8.5 to discern how climate change may affect future habitat suitability. Kernel density estimations, minimum convex polygons, and median distribution centers of White-tailed and Black-tailed occurrence records were examined between time-periods to discern the effects of anthropogenic westward expansion on both species’ distributions. Current ENMs were constructed from commonly …
Eutherian Biogeography During The Puercan North American Land Mammal Age (Paleocene, Earliest Danian): Problems And Potential Solutions, Jason Sterling Silviria
Eutherian Biogeography During The Puercan North American Land Mammal Age (Paleocene, Earliest Danian): Problems And Potential Solutions, Jason Sterling Silviria
Earth and Planetary Sciences ETDs
The Puercan North American Land Mammal Age (NALMA) is the earliest major North American terrestrial biochron of the Cenozoic era, spanning roughly the first one million years of the Paleogene period (Paleocene epoch, Danian stage; ~66.04-65.12 Ma). It is typified by the explosive ecomorphological diversification of the mammalian clade Eutheria (particularly our subclade, Placentalia), following the annihilation of non-avian dinosaurs and “archaic” mammal groups during the Cretaceous/Paleogene (K-Pg) mass extinction event. The spatiotemporal mode and tempo of Puercan eutherian diversification has long been the subject of debate, with disagreements over biogeographic zonation. The traditional model – based largely on well-sampled, …
Reconstructing The Paleoecology And Biogeography Of Rhinoceroses (Mammalia: Rhinocerotidae) In The Great Plains Of North America, Leading Up To Their Extinction In The Early Pliocene, Bian Wang
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Members of the family Rhinocerotidae first appeared in the middle Eocene and were one of most successful mammal groups of the Oligocene and Miocene in North America. Their extinction in the early Pliocene has been attributed to several causes, including cooling climate, an expansion of C4 grasslands, and faunal turnover favoring high-crowned, open habitat-adapted mammalian taxa. This study tests whether the extinction of North American rhinoceroses in the Great Plains was abrupt or gradual by examining changes in their paleogeographic distribution in a series of time-slices through the Barstovian, Clarendonian, and Hemphillian North American land-mammal ages. It further examines …