Earth Sciences Commons^™

Middle Miocene Paleoenvironmental Reconstruction Of The Central Great Plains From Stable Carbon Isotopes In Large Mammals, Willow H. Nguy

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

Middle Miocene (18-12 Mya) mammalian faunas of the North American Great Plains contained a much higher diversity of apparent browsers than any modern biome. This has been attributed to greater primary productivity, which may have supported greater browser diversity that commonly corresponds with densely vegetated habitats. However, several lines of proxy evidence suggest that open woodlands or savannas dominated middle Miocene biomes; neither of which support many browsers today. Stable carbon isotopes in mammalian herbivore tooth enamel were used to reconstruct vegetation structure of middle Miocene biomes.

Stable carbon isotopes in C₃ dominated environments reflect vegetation density and herbivores …

An Overview Of Secondary Aquifers In Nebraska, Dana Divine, Steven S. Sibray

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Interpretive Geologic Cross Sections Across Lower Platte North Natural Resources District, Nebraska (Ccs-20), Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Locomotion And Skeletal Morphology Of Late Cretaceous Mosasaur, Tylosaurus Proriger, Jesse A. Carpenter

Honors College Theses

Mosasaurs (Reptilia: Squamata) are apex marine predators from the Late Cretaceous (Turonian to Maastrichtian) epicontinental seas of North America, Africa, Europe, and Asia. From previous studies, it has been suggested that this group trends towards increased rib compactness, lengthening and increased posterior inclination of neural spines of intermediate and terminal caudal vertebrae to support a caudal fluke, and a transition from anguilliform to carangiform locomotion, closer to thunniform in pelagic adapted species. This study examined multiple Tylosaurus specimens using centrum length/width (CL/CW) and width/height (CW/CH) ratios along with neural spine height and angle of posterior inclination to (1) describe the …

Paleoecological Analysis Of The Clayton Formation (Paleocene) Near Malvern, Arkansas, Brenna J. Hart

Honors Theses

The Clayton Formation is a section of the Midway Group immediately above the Cretaceous-Paleogene boundary that contains marine fossils from the Paleocene Epoch. The formation is composed of glauconitic sand, clay, marl, and limestone. Fossils within the formation commonly occur in clay or are concentrated in conglomeratic lag lenses. To assess paleoecology of the region during the Paleocene, the Clayton Formation was sampled for fossil content at a distinctly visible exposure along Interstate 30 near Malvern, Arkansas, that was excavated as part of a landslide mitigation project. Complimentary sites were sampled nearby along the Ouachita River and behind a shopping …

Paleoimagery: The Artistic Restoration Of Dinosaurs And Prehistoric Life, Colin Mcnulty

Honors Projects

My purpose in creating this paper is to research a holistic view of paleontological illustration (also called paleoimagery or paleoart). A thorough history of paleoimagery is outlined from its roots in biblical illustration in the 17^th and 18^th centuries approaching the modern day. A two-fold examination of the utility of art to communicate science and its use within the science of paleontology is also given. This includes discussions of the specific components of art pieces that help them to successfully communicate scientific ideas and examples of how paleoimagery contributes to paleontology. The author then outlines the conception and …

A Floral Assemblage Of The Upper Cretaceous El Gallo Formation, El Rosario, Baja California, Mexico, Reilly F. Hayes, Marisol Montellano-Ballesteros, Gerardo Álvarez-Reyes, René Hernandez-Rivera, David E. Fastovsky

Senior Honors Projects

Over the past eight months, I have collaborated with paleontologists from the Universidad Nactional Autónoma de México to formally describe plant fossils they uncovered in Baja California between their 2013 and 2016 field seasons. We report the first floral assemblage of the dinosaur-aged El Gallo Formation, Baja California, Mexico, a small (82-specimen) collection of plant fossils from fossil soils contained within the 75.84 +/- 0.05 to 74.55 +/- 0.09 million-year-old El Disecado Member of the unit. A compound fruit belonging to the genus Operculifructus, previously reported from the 3.40 to 1.08 million year younger Cerro del Pueblo Formation, Coahuila, …

Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim

Electronic Theses and Dissertations

Despite being separated by millions of years of evolution, black bears (Ursus americanus) and brown bears (Ursus arctos) can be difficult to distinguish based on skeletal and dental material alone. Complicating matters, some Late Pleistocene U. americanus are significantly larger in size than their modern relatives, obscuring the identification of the two bears. In the past, fossil bears have been identified based on differences in dental morphology or size. This study used geometric morphometrics to look at overall differences in cranial shape and used step-wise discriminant analysis to identify specific characters that distinguish cranial morphology between …

Behavioral Paleoecology Of Lower Cambrian Deposit Foragers: Reinterpreting Looping And Meandering Traces Using Optimal Foraging Theory And Quantitative Analysis, Zachary Andrew Jensen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The early Cambrian was a period of transition during which the seafloor environment was changing from a microbial-mat-dominated environment to a bioturbation-dominated environment. The result was a patchy landscape of variable food resources for foraging burrowers to exploit. Looping trace fossils, such Psammichnites gigas and Taphrhelminthopsis nelsoni, appear in strata worldwide during this transitional period, and the ecological niche they filled is a subject of debate among ichnologists. The objectives of this study are (1) to determine the foraging strategies preserved by looping traces through the application of optimal foraging theory and quantitative analysis, and (2) use those results to …

Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej

Electronic Theses and Dissertations

Fossil Agamidae from Western Australia have been the subject of limited study. To aid in fossil agamid identification, Hocknull (2002) examined the maxilla and dentary of several extant species from Australia and determined diagnostic characters for various species groups. In the study here, fossil agamids from two localities in Western Australia, Hastings Cave and Horseshoe Cave, were examined, grouped, and identified to the lowest unambiguous taxonomic level. Morphometric analyses were conducted to compare morphotypes, and find additional diagnostic characters. From Hastings Cave there were two maxilla morphotypes and three dentary morphotypes. Based on identifications, taxa present at this locality were …

Black Bears (Ursus Americanus) Versus Brown Bears (U. Arctos): Combining Morphometrics And Niche Modeling To Differentiate Species And Predict Distributions Through Time, Theron Michael Kantelis

Electronic Theses and Dissertations

Late Pleistocene American black bears (Ursus americanus) often overlap in size with Pleistocene brown bears (U. arctos), occasionally making them difficult to diagnose. Large U. americanus have previously been distinguished from U. arctos by the length of the upper second molar (M2). However, the teeth of fossil U. americanus sometimes overlap size with U. arctos. As such, there is need for a more accurate tool to distinguish the two species. Here, 2D geometric morphometrics is applied to the occlusal surface of the M2 to further assess the utility of this tooth for distinguishing U. americanus and …

Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016, Douglas Hallum, Sue Olafsen Lackey

Conservation and Survey Division: Faculty and Staff Publications

The High Plains Aquifer underlies much of Nebraska (Figure 1). It is the primary source of groundwater within the Upper Loup Natural Resources District (ULNRD) of central Nebraska (Figure 2). Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. A general lack of water level observations in the region (Figure 3), recently developed groundwater irrigated acres along the upper Calamus River (Figure 4), falling spring water levels measured in existing irrigation wells (Figure 5), and a stable to falling stream …

Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Evolution Of Floral Zygomorphy In Androecium And Corolla In Solanaceae, Jingbo Zhang, Peter Stevens, Wenheng Zhang

Biology Department Faculty Works

In Solanaceae, a group dominated by actinomorphic‐flowered species, floral zygomorphy is frequently observed among the early‐branching clades. Morphological studies indicated that a zygomorphic androecium is much more common than a zygomorphic corolla in the family. Ontogenic studies suggested the evolution of floral zygomorphy in these two whorls is independent. Here, we have examined the evolution of floral symmetry in the androecium and corolla in Solanaceae. The character states of floral symmetry were assembled for androecium and corolla separately, and ancestral state reconstructions were carried out at both the genus and species levels for Solanaceae and its outgroups. Correlation tests were …

Phylogenetic Patterns Of Rarity In A Regional Species Pool Of Tropical Woody Plants, M. Loza, Iván Jiménez, Peter Jørgensen, Gabriel Arellano, Manuel Macía, Vania Torrez, Robert Ricklefs

Biology Department Faculty Works

AimRarity, which is believed to influence extinction risk, can be defined in terms of local abundance, geographical range size and habitat breadth. Phylogenetic patterns in these attributes provide insight into the extent to which rarity and extinction risk are conserved during evolution and the potential for species‐level heritability. We evaluated phylogenetic signal (i.e., related species resembling each other more than species drawn at random) and evolutionary conservatism (similarity among related species exceeding that expected from a Brownian model of evolution) in three axes of rarity (local abundance, geographical range size and habitat breadth) among species in a regional pool of …

Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nebraska is known by vertebrate palaeontologists as the place in North America where there is a very complete Cenozoic geologic record of mammalian evolution over the last thirty-five million years or so. All you have to do is visit any of the many major natural history museums in the USA and in many countries around the world, including the UK, to see fossil skulls, articulated skeletons and large slabs of rock containing bones of fossil mammals from Nebraska to verify this assertion. Nebraska is also the site of Cretaceous rocks containing the oldest known Cretaceous fossil flower and many other …

Dielasma Or Tunethyris? A Taxonomic Conundrum, Howard R. Feldman, Talia J. Belowich, Tova Braver, Sarah Laks

Lander College for Women - The Anna Ruth and Mark Hasten School Publications and Research

A new species of a dielasmid brachiopod from the Triassic Saharonim Formation of Makhtesh Ramon, southern Israel, was discovered in Anisian-Ladinian limestones that alternate with calcareous shales. The environment of deposition was an open shelf with normal salinity. The new species is homeomorphic with Paleozoic forms, but may not belong to the genus Dielasma; however, it may be a species of Tunethyris, a Triassic genus from Tunisia. If the Triassic specimens belong to the Paleozoic genus Dielasma, an important new Lazarus genus is added to the systematic literature. However, if the specimens belong to the Triassic Tunethyris, …

A Unique Petroglyph Carving On The Shawangunk Ridge, Lower Hudson Valley, New York, Howard R. Feldman

Lander College for Women - The Anna Ruth and Mark Hasten School Publications and Research

A unique circular petroglyph from the Shawangunk Ridge in the lower Hudson Valley, New York was found carved into the resistant metaconglomerate/quartzitic rock not far from Mohonk Mountain House. The Shawangunk Formation crops out near Rosendale, New York and extends in a general southwestward direction accessible along Route 17 near Wurtsboro, again at the Delaware Water Gap and then can be traced in into Pennsylvania and Virginia. The ridge and surrounding area (e.g. Wallkill Valley) is lacking in chert, a vital raw material used in the carving of petroglyphs (Feldman, et al., 2016). However, there are numerous other examples of …

2016 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, Connie Reimers-Hild

Conservation and Survey Division: Faculty and Staff Publications

The effective management of Nebraska’s water resources is evermore challenged by variations in weather, climate, technology, socioeconomic policies, and regulation. Anthropogenic climate change, declining water tables and stream flows, increasing demands on freshwater, aging water infrastructure, fiscal constraints, and impacts on aquatic organisms are particularly imminent challenges in Nebraska and around the world (Pahl-Wostl et al., 2013; Pittock et al., 2008; USACE, 2010). Sustaining freshwater ecosystem services in the face of emerging environmental threats presents an immense societal dilemma worldwide (Pittock et al., 2013; Rockström et al., 2009, Millenium Ecosystem Assessment, 2005). The rapidly changing conditions of water resources in …

Five Species Of Fossil Equids Preserved In-Situ At Ashfall Fossil Beds, Rick E. Otto

University of Nebraska State Museum: Programs Information

Fully articulated, three-dimensionally preserved skeletons from five species of fossil Equids are now represented, and preserved in-situat the Ashfall Fossil Beds in northcentral Nebraska. The site is well known for dozens of barrel-bodied rhino (Teleoceras major) skeletons. A diversity of horse species that inhabited Nebraska during the late Miocene Epoch have been exposed in the fossil bed. Genera include Cormohipparion, Neohipparon, Pliohippus, Protohippus, and Pseudhipparion. An exceptionally well-preserved skeleton of the small-sized, three-toed species Pseudhipparion gratumwas recently exposed, and is on display only a few feet from where visitors stand.

Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California, Trenton J. Ryan

Cal Poly Humboldt theses and projects

The Pullen and Saint George formations are coeval late Miocene-early Pliocene sedimentary formations in northwestern California. The type localities of both formations were studied from a micropaleontologic perspective that focused primarily on Foraminifera, but with additional observations of other fossil groups to reconstruct their past depositional environments. The results obtained in this study provided a photomicrographic inventory of the microfossils from both formations, aided in investigating changes in paleobathymetry of the formations during the late Miocene and early Pliocene based on Foraminifera, and allowed for interpretation of paleoecological signals from the foraminiferan associations. Foraminifera have not been previously described in …

Quantifying Ephemeral Gully Erosion With Photogrammetry Surveying, C. B. Weerasekara, A. Y. Shechukov

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Preservation Of Sea Anemone Burrows In Silurian (~432 Million Years Old) Carbonate Rocks Of Southeastern Indiana, Usa, Marissa Tomin

Williams Honors College, Honors Research Projects

Preservation of trace fossils (ichnofossils) in siliciclastic environments is often quite different from preservation in carbonate environments, representing an important source of variation that must be well understood in order to enhance interpretations of paleoenvironments and paleoecology. This study focuses on Conostichus, a relatively common burrow constructed by solitary sea anemones. These trace fossils are generally well-preserved (i.e., they display detailed external features) in siliciclastic rocks but are typically little more than conical masses in carbonate rocks. However, certain specimens recovered from the middle Silurian Massie Formation at the Napoleon quarry of southeastern Indiana are composed entirely out of …

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …

Early Miocene Quantitative Calcareous Nannofossil Biostratigraphy From The Tropical Atlantic, Waheed A. Albasrawi

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

Quantitative analysis for the Lower Miocene of Ocean Drilling Program Hole 959A from the West African margin was performed to document all the calcareous nannofossil biostratigraphic events present. Combined with data from previous investigations of the Lower Miocene from the tropical Atlantic, this research identifies and tests the viability of markers used in current zonation scheme, identifies alternative markers for age boundaries, and examine statistically the most probable order of event in the Lower Miocene using the Ranking and Scaling method (RASC).

The examination of Hole 959A was performed on a 112 samples. Seven additional sites that collectively span the …

A Gis Analysis Of Waulsortian-Like Mounds In The Mississippian Of Kentucky And Tennessee, Philip Roberson

Scholars Week

Following a mass extinction nearly 365 million years ago, bryozoans and crinoids replaced corals and stromatoporoids as the dominant framework organisms in reefs and, during the very earliest part of the Carboniferous period, they built reef-like structures that are known from Europe, North America and Africa. They are characterized by large size, a matrix of carbonate mud, and their major framework organisms.

Waulsortian-like mounds occur in geographically isolated patches in outcrop and in the subsurface of central Tennessee and Kentucky where they are associated with hydrocarbon production. These mounds have the same characteristic organisms as the European mounds and do …

Lessons From The Past: Unfolding The Dynamics Among Climate, Balkan Landscapes, And Humans Over The Past Millennium, Charuta J. Kulkarni

Dissertations, Theses, and Capstone Projects

The primary objective of this doctoral dissertation is to reconstruct the environmental history of the Central Balkans (Serbia) over the past millennium utilizing biological proxies (pollen, spores, and charcoal), geochemical signals through X-ray fluorescence (XRF), statistical analyses, and atomic mass spectrometry (AMS) ¹⁴C chronology. This dissertation establishes the first chronological framework for vegetation-landscape changes in Serbia and discusses the role of humans and climate as underlying processes.

Chapter 1 discusses the background and the nature of the research problem followed by the extensive literature review on the topic of the Holocene climate and paleoecology. The state of Holocene paleoecology …

Turtles From An Arkadelphia Formation—Midway Group Lag Deposit (Maastrichtian—Paleocene), Hot Spring County, Arkansas, Usa, Martin A. Becker, Harry M. Maisch Iv, John A. Chamberlain Jr.

Publications and Research

The Arkadelphia Formation—Midway Group (Maastrichtian—Paleocene) contact near Malvern, Arkansas preserves a K-Pg boundary assemblage of turtle species consisting of skull, shell, and non-shell postcranial skeletal elements. The Malvern turtles are preserved within a coquina lag deposit that comprises the basalmost Midway Group and also contains an abundance of other reptiles, as well as chondrichthyans, osteichthyans, and invertebrates. This coquina lag deposit records a complex taphonomic history of exhumation and reburial of vertebrate skeletal elements along a dynamic ancestral shoreline in southwestern Arkansas during the late Cretaceous-early Paleocene. Based on stratigraphic occurrence, the Malvern turtle assemblage indicates that these marine reptiles …

Depositional Model Of A Late Cretaceous Dinosaur Fossil Concentration, Lance Formation, Summer Rose Weeks

Loma Linda University Electronic Theses, Dissertations & Projects

A large Maastrichtian, nearly monospecific bonebed in the Lance Formation in eastern Wyoming has yielded 13,000 bones and fragments since 1996. Though excavation of the site continues, little is known of the circumstances and processes of deposition. This study aims to provide a depositional model for the bonebed. To accomplish this task we utilized 1D facies analysis of surrounding units and 3D analysis of the bonebed. The nature of the outcrop limited facies analysis to 1D. Four measured stratigraphic sections, each containing the bonebed unit, were taken and used in facies analysis. In addition, laterally continuous units were observed and …

Three-Dimensional Architecture And Hydrostratigraphy Of Cross-Cutting Buried Valleys Using Airborne Electromagnetics, Glaciated Central Lowlands, Nebraska, Usa, Jesse T. Korus Dr., Robert Matthew Joeckel, Dana P. Divine, Jared D. Abraham

Conservation and Survey Division: Faculty and Staff Publications

Buried valleys are characteristic features of glaciated landscapes, and their deposits host important aquifers worldwide. Understanding the stratigraphic architecture of these deposits is essential for protecting groundwater and interpreting sedimentary processes in subglacial and ice-marginal environments. The relationships between depositional architecture, topography and hydrostratigraphy in dissected, pre-Illinoian till sheets is poorly understood. Boreholes alone are inadequate to characterize the complex geology of buried valleys, but airborne electromagnetic surveys have proven useful for this purpose. A key question is whether the sedimentary architecture of buried valleys can be interpreted from airborne electromagnetic profiles. This study employs airborne electromagnetic resistivity profiles to …