Paleontology Commons^™

Community Structure Analysis Of Turtles With Application To The Early Pliocene Gray Fossil Site, Julian Conley

Electronic Theses and Dissertations

Turtles are important components of ecosystems around the world, with diverse ecological niches and adaptations. However, there are few detailed studies of how turtle community structure reflects local environments. This project applied techniques of community structure analysis to sites across the United States to infer past ecosystem and environmental conditions of the early Pliocene Gray Fossil Site (GFS) in northeastern Tennessee based on the ancient turtle community. Results indicate extant turtle community structure closely reflects environmental conditions, and that ancient turtle communities can be used to infer climate and habitat conditions of past ecosystems. Application to the GFS turtle community …

The Paleoecology Of High-Elevation Bison In The Greater Yellowstone Ecosystem And Implications For Modern Bison Conservation, Darian Bouvier

Electronic Theses and Dissertations

The national mammal of the United States, the American Bison (Bison bison) was once nearly extinct. Populations have recovered to the degree that thousands roam the Great Plains today. Due to their large numbers and body size, this species has an oversized impact on the ecological communities where it lives and is considered a keystone herbivore in modern North American grasslands. This study explores the detailed, seasonally resolved, paleoecology of seven bison from the Greater Yellowstone Ecosystem during the Late Holocene through stable isotope analyses and species niche modeling. Isotopic analyses of δ¹³C, δ¹⁵N, …

An Evaluation Of Castor Californicus And Implications For The Evolution And Distribution Of The Genus Castor (Rodentia: Castoridae) In North America, Kelly Lubbers

Electronic Theses and Dissertations

The genus Castor is represented in Eurasia by Castor fiber, North America by C. canadensis, and has been in North America since the late Miocene. This study aims to assess whether morphology of Miocene-Pliocene C. californicus and extant C. canadensis are distinctly different. Specimens of Castor were compared using geometric morphometrics on cranial material and linear measurements of postcranial material. Species occurrence data were compared with past and future climate data to assess Castor distribution in North America through time. Results show that C. canadensis is highly variable in both cranial and postcranial morphology and C. californicus falls …

The Diatom Dark Ages: Identification Of Mid-Cretaceous Arctic Platform Diatoms From The Basal Transgression Of The Kanguk Formation, Devon Island, Nunavut, Canada, Megan Heins

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

The lower part of the mid-Cretaceous Kanguk Formation (Lower Turonian interval) contains an important paleontological record crucial to the characterization of a poorly known interval of fossil marine diatoms history. Kanguk Formation mudstones are exposed in a ~200 m-thick section on Devon Island, Nunavut, Canadian High Arctic. Diatoms at this location are well-preserved due to shallow burial on this Arctic Platform site. The rock sequence was protected from glacial erosion that removed much of the Cretaceous record by being down-faulted in a linear graben. Study of these well-preserved fossil diatoms allows for a documentation of the assemblage, identification of potentially …

Functional Morphology And Taphonomy Of Ordovician–Silurian Diploporan Echinoderms, Stephen Ashley Hill

USF Tampa Graduate Theses and Dissertations

Diploporan echinoderms were one of the most speciose groups of stemmed echinoderms during the Ordovician. Despite this widespread abundance, the fossil record of diploporan fauna consists primarily of incomplete specimens, with complete specimens being rare. While the theca, or body, is more commonly preserved, the feeding appendages and the attachment structures (i.e. stems or holdfasts) are seldomly preserved. Insight into these features is highly valuable to the understanding the paleoecology, like the feeding and respiratory strategies, of these enigmatic creatures.

One group of diploporan echinoderms which does have an extensive fossil record, is the Holocystites Fauna, primarily known from the …

Two New Late Quaternary Avifaunas From The East-Central Great Basin With The Description Of A New Species Of Falco, Steven D. Emslie, Jim I. Mead

Western North American Naturalist

We report 2 new late Quaternary avifaunas from cave deposits in Snake Valley, White Pine County, eastern Nevada, that provide new records of extinct and extant species in the east-central Great Basin. These avifaunas collectively represent at least 24 species, including the most northern inland record of California Condor (Gymnogyps californianus) in western North America and a new species of kestrel (Falco sp.) described herein. Two extralimital living species also were identified—the Harlequin Duck (Histrionicus histrionicus) and Snowy Owl (Bubo scandiacus)—and are the first fossil records of these species in the Great Basin. …

Analysis Of Fossil Pollen From A Pleistocene Cypress Forest Preserved On The Northern Gulf Of Mexico Continental Shelf, Kathryn Joyce Garretson

Master's Theses

This study presents the findings of fossil pollen analysis performed on terrestrial sediments preserved on the northern Gulf of Mexico continental shelf (site hereafter known as the Underwater Forest or DF). This research aims to establish vegetation composition on a continental shelf glacial refuge and provide a better understanding of vegetation response to sea-level rise. Two cores (15DF1 and 15DF3B) located at different locations within the forest were recovered and analyzed. Pollen results from both cores were similar, with high percentages of Taxodium and Nyssa pollen in the lowermost sections reflecting an assemblage typical of contemporary baldcypress swamps. Pollen assemblages …

Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson

2022 Symposium

The Sandwich Bluff Formation of the James Ross Basin of Antarctica has recently yielded a group of five late Cretaceous dinosaurs that lived contemporaneously with each other, a first for Antarctica. These five dinosaurs include fragmentary remains of two differently sized elasmarian ornithopods, a possible megaraptor, a hadrosaur, and a nodosaur. In this study we will construct a model of the ecological relationships of late Cretaceous Antarctica. Additionally, we will look at what specific factors allowed this group of four herbivores and a carnivore to coexist in a restricted locality and what niches were filled by each species. Methods to …

Ontogenetic Niche Shift As A Driver Of Community Structure And Diversity In Non-Avian Dinosaurs, Katlin M. Schroeder

Biology ETDs

As some of the most charismatic megafauna to ever walk the earth, the physiology, morphology, growth and evolution of non-avian theropods has been studied exhaustively, yet little is understood about their roles in ecosystems as juveniles. For carnivorous megatheropods, which exceed 1,000kg in mass yet hatched from eggs of limited size, the likelihood of utilizing different prey through ontogeny was high, simply by proxy of the immense difference in size between adults and juveniles. We found these ontogenetic niche shifts, evidenced by significantly different dental microwear in Tyrannosaurids, to have excluded dinosaurian mesocarnivores from Mesozoic communities. The few dinosaurian mesocarnivores …

Rodent Dental Microwear Texture Analysis As A Proxy For Fine-Scale Paleoenvironment Reconstruction, Jenny H. E. Burgman

Graduate Theses and Dissertations

Dental microwear texture analysis (DMTA) of fossil fauna has become a valuable tool for dietary inference and paleoenvironment reconstruction. Most of this work has utilized larger taxa with larger home ranges. These studies may result in broader-scale habitat inferences that could mask the details of complex mosaic habitats. Rodent DMTA offers an opportunity to work at finer spatial scales because most species have smaller home ranges. Rodents are also keystone species within their ecosystems, abundant, ubiquitous, and found in many fossil deposits. These attributes make them excellent proxies for environmental reconstructions. However, the application of DMTA to rodents remains relatively …

Halodash: The Deep And Shallow History Of Aquatic Life's Passages Between Marine And Freshwater Habitats, Eric T. Schultz, Lisa Park Boush

EEB Articles

This series of papers highlights research into how biological exchanges between salty and freshwater habitats have transformed the biosphere. Life in the ocean and in freshwaters have long been intertwined; multiple major branches of the tree of life originated in the oceans and then adapted to and diversified in freshwaters. Similar exchanges continue to this day, including some species that continually migrate between marine and fresh waters. The series addresses key themes of transitions, transformations, and current threats with a series of questions: When did major colonizations of fresh waters happen? What physiographic changes facilitated transitions? What organismal characteristics facilitate …

Dental Morphology In A Juvenile Mammal From The Late Cretaceous Of South America: Tooth Eruption And Development., Kayla E Newton

Electronic Theses and Dissertations

Meridiolestids are a diverse and distinct clade of Cretaceous–Miocene South American dryolestoid mammals ranging in size from small shrew-sized insectivores to large dog- sized omnivores. Cronopio dentiacutus from the Cenomanian La Buitrera locality, Rio Negro Province, Argentina (Candeleros Fm.) is the oldest and best known of them, represented by skull material and associated jaws. A juvenile skull as attributed to Cronopio dentiacutus, based on tooth size and morphology, was collected from the type locality. The specimen includes the skull and both articulated lower jaws. The fossil is poorly ossified and partially flattened; CT scanning reveals most of the dentition …

Community Structure Analysis Of Mammals Found At The Gray Fossil Site, Tn, Sarah Clark

Electronic Theses and Dissertations

The early Pliocene Gray Fossil Site (GFS) is a biodiverse site with a unique faunal assemblage that represents one of few sites of its age in eastern North America. A community structure analysis of the mammals at GFS was done to characterize species and better understand the paleoenvironment. Data and was gathered from twenty modern communities and five late Neogene sites to compare with GFS. Species from these 26 sites were categorized by body size, locomotor mode, cheek tooth crown height, and diet to characterize niches occupied. Descriptive statistics contrasted proportions of species within categories across communities. Discriminant function analyses …

Interdisciplinary Studies Masters Degree In Anthropological & Science Based Education, Robert Porter

Electronic Theses, Projects, and Dissertations

The goal of this project is to develop anthropological and science-based curricula that will emphasize a place-based approach while actively engaging students in their education. I developed two curricula for elementary aged students in San Bernardino. The first curriculum was based anthropologically on the local history of indigenous groups and early San Bernardino history. The second was based on paleontology here in California with a focus on dinosaurs and fossils.

To improve and validate the curricula I sent the examples to educational experts and had them critique the lessons and information provided. Then I used their input to improve the …

Nebraska Statewide Groundwater-Level Monitoring Report 2021, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

This report is a synthesis of groundwater-level monitoring programs in Nebraska. It is a continuation of the series of annual reports and maps produced by the Conservation and Survey Division (CSD) of the University of Nebraska in cooperation with the U.S. Geological Survey (USGS) since the 1950s. Groundwater-level monitoring began in Nebraska in 1930 in an effort to survey the state’s groundwater resources and to observe changes in its availability on a continuing basis. The CSD and USGS cooperatively developed, maintained, and operated an observation-well network throughout the state. These two agencies were responsible for collecting and archiving this information, …

Baseflow And Water Resilience Variability In Two Water Management Units In Southeastern Brazil, Lucas Vituri Santarosa, Didier Gastmans, Troy E. Gilmore, Jan Boll, Sebastian Balbin Betancur, Vitor Fidelis Monteiro Gonçalves

Conservation and Survey Division: Faculty and Staff Publications

Changes in climate and water demand in densely populated regions increasingly affect hydrological systems, and, in turn, impact socioeconomic conditions. In this case study, we identify how the hydrogeological frameworks of two water resource management units, Tietê-Jacaré (TJ) and Piracicaba-Capivari-Jundiaí (PCJ) in Sao Paulo state (Brazil), control the baseflow processes and resilience in the face of streamflow fluctuations in response to anthropogenic activities and climate variation. The results reveal between 40% and 75% contributions of baseflow to total streamflow in basins overlying crystalline and sedimentary aquifers. The basins in PCJ which mostly overly crystalline aquifers, have shorter water residence times …

The Naming Of Homo Bodoensis By Roksandic And Colleagues Does Not Resolve Issues Surrounding Middle Pleistocene Human Evolution, Eric Delson, Chris Stringer

Publications and Research

Roksandic et al. (2022) proposed the new species name Homo bodoensis as a replacement name for Homo rhodesiensis Woodward, 1921, because they felt it was poorly and variably defined and was linked to sociopolitical baggage. However, the International Code of Zoological Nomenclature includes regulations on how and when such name changes are allowed, and Roksandic et al.'s arguments meet none of these requirements. It is not permitted to change a name solely because of variable (or erroneous) later use once it has been originally defined correctly, nor can a name be modified because it is offensive to one or more …

2022 Nebraska Water Leaders Academy Final Report, Mark E. Burbach, Robert Matthew Joeckel, Brooke Mott, Gina S. Matkin

Conservation and Survey Division: Faculty and Staff Publications

Fifteen participants completed the 2022 Water Leaders Academy bringing the total number of graduates to 168 since the inception of the program in 2011. Assessments of participants’ transformational leadership skills, champion of innovation skills, water knowledge, engagement with water issues, civic capacity, entrepreneurial leadership behaviors, and boundary spanning skills increased significantly over the course of the year, according to both the participants and their raters. Feedback from the participants was highly positive and constructive. Academy planners are addressing participant concerns. Results of the program assessment indicate that the curriculum is meeting Academy objectives. Therefore, only minor changes are planned for …

Amphibians And Reptiles Of Nebraska Coloring Pages, John Lokke

Conservation and Survey Division: Faculty and Staff Publications

Black and white images from original art by John Lokke. Suitable for coloring pages. Published by the Nebraska Maps & More Store at the School of Natural Resources, University of Nebraska - Lincoln.

The Revised Systematics And Paleoecology Of The Devonian Stemless Crinoid Genus Edriocrinus Hall, 1858, Catherine E. Herbert

Theses and Dissertations--Earth and Environmental Sciences

New morphological observations of Edriocrinus Hall, 1858, enable a modern, holistic view of this unusual crinoid genus, previously included in the Superorder Flexibilia (Zittel, 1895) Wright et al., 2017. Re-analysis of Edriocrinus suggests that the genus should now be assigned to the Order ‘Dendrocrinida’ within the Magnorder Eucladida Wright, 2017 based on the five infrabasals, single radianal in the cup, absent anal sac, and non-pinnulate arms with rectangular uniserial brachials. Moreover, examination of the slight variations separating the current 14 Edriocrinus species indicates that these “species” are likely ecophenotypes. The current Edriocrinus species are revised based on firmly bound calyx …