Paleobiology Commons^™

Paleoenvironmental Reconstruction Of Quaternary Saltville, Virginia, Using Ostracode Autecology, Austin Gause

Electronic Theses and Dissertations

The Saltville valley in southwestern Virginia is home to Quaternary localities containing paleontological and archaeological remains. Historically the valley has been mined for salt and the small lakes, ponds and springs along the valley floor have a brackish signature. A preliminary report on the site’s ostracode fauna suggested that the site’s water was not always saline. This study analyzed modern and Quaternary ostracodes to understand the valley’s hydrologic and chemical evolution. Sediments contained primarily freshwater species, including the environmentally sensitive Candona crogmaniana. The presence of Pelocypris tuberculatum and a new Fabaeformiscandona species throughout a vertical section spanning ...

An Unusual Mastodon Revisited: Providing A Regional Focus For Mammut Americanum (Proboscidea, Mammutidae) In The Southeast, Matthew Inabinett

Electronic Theses and Dissertations

A century ago, two large American mastodon Mammut americanum specimens from coastal South Carolina were mounted for display at Amherst College. Their robust build, broad and pentalophodont third molars, and well-developed mandibular tusks were noted as unusual. Here, these specimens are redescribed; three additional mastodon mandibles from the same region of South Carolina are also described. Though collection information on these specimens is sparse, they appear to span >150 ka in the Middle to Late Pleistocene, and probably include the first report of Mammut from the earliest-Rancholabrean Ten Mile Hill Formation. Some “unusual” features — moderately to extremely broad third molars ...

A Southeastern North America River Community Forty-Thousand Years Ago, Zack J. Quirk, Dennis B. Blanton

Georgia Journal of Science

Understanding how past communities have been shaped by environmental alterations can provide insight into the impacts of future climate change. Local climate and river systems have changed significantly over the last glacial maximum, but little is known about the communities of the Georgian Coastal Plain earlier in the period. Plant fossils from Coffee Bluff, a Quaternary organic river deposit of the Ocmulgee River in southeastern Georgia, were used to determine past environmental and climatic conditions. The paleoflora were found imbedded in a mud matrix and were removed by a slaking method; they were later identified and separated to respective ecological ...

An Assessment Of Convergence In The Feeding Morphology Of Xiphactinus Audax And Megalops Atlanticus Using Landmark-Based Geometric Morphometrics, Edward Chase Shelburne

Master's Theses

Convergence is an evolutionary phenomenon wherein distantly related organisms independently develop features or functional adaptations to overcome similar environmental constraints. Historically, convergence among organisms has been speculated or asserted with little rigorous or quantitative investigation. More recent advancements in systematics has allowed for the detection and study of convergence in a phylogenetic context, but this does little to elucidate convergent anatomical features in extinct taxa with poorly understood evolutionary histories. The purpose of this study is to investigate one potentially convergent system—the feeding structure of Xiphactinus audax (Teleostei: Ichthyodectiformes) and Megalops atlanticus (Teleostei: Elopiformes)—using a comparative anatomical approach ...

Reorganization Of Surviving Mammal Communities After The End-Pleistocene Megafaunal Extinction, Anikó B. Tóth, S. Kathleen Lyons, W. Andrew Barr, Anna K. Behrensmeyer, Jessica L. Blois, René Bobe, Matt Davis, Andrew Du, Jussi T. Eronen, J. Tyler Faith, Danielle Fraser, Nicholas J. Gotelli, Gary R. Graves, Advait M. Jukar, Joshua H. Miller, Silvia Pineda-Munoz, Laura C. Soul, Amelia Villaseñor, John Alroy

Faculty Publications in the Biological Sciences

Large mammals are at high risk of extinction globally. To understand the consequences of their demise for community assembly, we tracked community structure through the end- Pleistocene megafaunal extinction in North America.We decomposed the effects of biotic and abiotic factors by analyzing co-occurrence within the mutual ranges of species pairs. Although shifting climate drove an increase in niche overlap, co-occurrence decreased, signaling shifts in biotic interactions. Furthermore, the effect of abiotic factors on cooccurrence remained constant over time while the effect of biotic factors decreased. Biotic factors apparently played a key role in continental-scale community assembly before the extinctions ...

Assessing Diagenetic Conditions In The Late Triassic Chinle Formation Through Petrographic And Geochemical Analysis Of Phytosaur Teeth, John Fortner

Earth Sciences Theses and Dissertations

The Upper Triassic (Norian; ~227-208 Ma) Chinle Formation of Petrified Forest (PeFo) National Park was deposited during a time of major tectonic breakup and profound changes in atmospheric circulation and faunal compositions. Little has been done however to assess whether surficial paleoenvironmental trends related to deterioration of the Late Triassic Megamonsoon resulted in similar trends in the early diagenetic environment. Here, we use phytosaur tooth dentin as a proxy for diagenetic conditions in the Chinle of PEFO, as its greater susceptibility to chemical alteration relative to enamel makes it an excellent substrate from which changing diagenetic conditions may be studied ...

Changes In Mammalian Abundance Through The Eocene-Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham

Dissertations & Theses in Earth and Atmospheric Sciences

Marine records show major cooling during the Eocene-Oligocene Climate Transition (EOCT). Most proxy studies in the White River Group suggest drying across the EOCT, and some suggest cooling. The lower resolution continental record has hindered a direct correlation of the marine climate record to Nebraska. I explore various correlation schemes and what they imply for faunal changes. This study compiles and analyzes data from 4,875 specimens in the University of Nebraska State Museum (UNSM) collection to test the hypothesis that climate change across the Eocene-Oligocene (E-O) boundary caused significant abundance changes in mammals. A series of binning schemes was ...

An Early Modern Human Outside Africa, Eric Delson

Publications and Research

Analysis of two fossils from a Greek cave has shed light on early hominins in Eurasia. One fossil is the earliest known specimen of Homo sapiens found outside Africa; the other is a Neanderthal who lived 40,000 years later.

Identifying Dietary And Migratory Patterns Of Illinois Woolly Mammoth Populations Using Isotope Analysis Of Carbon, Oxygen, And Strontium, Matthew Harrington, Chris Widga, Al Wanamaker, Doug Walker

Celebration of Learning

The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboard throughout the Late Pleistocene (100-10 Ka). Although it is recognized that woolly mammoths coincided with and lived in a region heavily influenced by glacial ice sheets, little is known about their dietary or migratory behavior. This study classifies and provides insight into the diet and mobility of Midwestern mammoths by analyzing stable isotopes of carbon, oxygen, and strontium preserved in the tooth enamel of these extinct elephantids. A woolly mammoth tooth from Moline, IL, was bulk-sampled and micromilled to extract the aforementioned isotopes from the base of ...

Genetic Sequencing For Measuring Biodiversity In Recent And Ancient Marine Sediments, Lauren Judge

Celebration of Learning

Taxonomic biodiversity, measured by counting the number of species present in a given area, is the most common method of capturing ecosystem biodiversity in recent and ancient environments. While this method is widely accepted, it is limited by poor preservation and identification of many individuals, making it impossible to include every species within an ecosystem and resulting in the loss of some diversity information. To address this issue, we measured the genetic biodiversity (in which species are determined based on sequencing of their DNA) of shallow marine ecosystems by extracting and sequencing the 18S ribosomal gene from bulk carbonate sediment ...

A Multi-Proxy Paleoecological Reconstruction Of Holocene Climate, Vegetation, Fire And Human Activity In Jamaica, West Indies, Mario A. Williams

Electronic Theses and Dissertations

Jamaica is located in the Caribbean biodiversity hotspot and has a rich flora and fauna, most notably characterized by exceptional levels of plant endemism. These natural resources are imperiled by climate change and increasing anthropogenic pressures, therefore highlighting the importance of implementing effective conservation programs to mitigate ecosystem degradation. Paleoecological studies that investigate the diversity and distributions of organisms and their habitats over millennial timescales provide critical long-term spatial and temporal context for the assessment of contemporary environmental problems. Lake sediments are a highly useful archive for the study of prehistoric climate and ecological changes, as biological, chemical and geophysical ...

Giant Beaver Palaeoecology Inferred From Stable Isotopes, Tessa Plint, Fred J. Longstaffe, Grant Zazula

Earth Sciences Publications

This is a multi-individual (n = 11), stable carbon and nitrogen isotope study of bone collagen (δ¹³C_col and δ¹⁵N_col) from the giant beaver (genus Castoroides). The now-extinct giant beaver was once one of the most widespread Pleistocene megafauna in North America. We confirm that Castoroides consumed a diet of predominantly submerged aquatic macrophytes. These dietary preferences rendered the giant beaver highly dependent on wetland habitat for survival. Castoroides’ δ¹³C_col and δ¹⁵N_col do not support the hypothesis that the giant beaver consumed trees or woody plants, which suggests that it ...

Using X-Ray Fluorescence To Analyze Fire Impacted Soil And Vegetation Composition, Dylan Darter

Kansas State University Undergraduate Research Conference

In our lab, I am using an X-ray fluorescence (XRF) to measure the concentrations of metals in sediments from subalpine lakes. Our goal is to measure the biogeochemical consequences of wildfires over the last 2000 years. This study looks at the elemental composition of different lake cores, and vegetation samples from areas of the “Big Burn” fire of 1910. This fire burned across several states in the Rocky Mountain region. With our XRF data we are able to see how the fire impacted the soils and how long after the fire proper soil composition can occur. This study can be ...

Index

Bulletin of the University of Nebraska State Museum

No abstract provided.

A Description Of A Population Of Rugose Horn Corals In The Whitewater Formation (Richmondian, Ordovician) Camden, Oh, Campbell F. Bortel

The Research and Scholarship Symposium (2013-2019)

The Whitewater Formation, part of the upper Ordovician period, is predominately a fossiliferous wavy limestone unit interbedded with fossiliferous shales (State of Ohio, 2012). These shales contain a variety of marine invertebrates including various species of brachiopods, bryozoans, trilobites and an abundance of rugose horn corals. The purpose of this project was to collect and describe a population of rugose corals from several outcrops exposed in Camden, OH. These outcrops are exposed along OH-127 and OH-725 as road cuts. Over 500 corals were collected, sorted for complete specimens, and numerically categorized into a dataset. Each coral was linked to its ...

Using Ct Scans To Describe An Allosaurus Skull (Dinosauria: Theropoda), Jordan C. Oldham

The Research and Scholarship Symposium (2013-2019)

In 2001, an Allosaurus skull (CMP 279) was discovered in the Skull Creek Basin in Moffat County, Colorado. The skull is one of the most complete for the species and even contains the hyoid bones, which are usually not present. The skull is now permanently mounted, for display purposes, thus making the study of the individual bones difficult for producing a paleo-anatomical description. Computed Tomography (CT) scans of CMP 279 were created in 2017 and then made available for this study in 2019. CT scans are being used to investigate internal anatomy of skulls such as the endocranial cavity, sinuses ...

The Accelerating Influence Of Humans On Mammalian Macroecological Patterns Over The Late Quaternary, Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons, Jonathan L. Payne, Amelia Villaseñor

Faculty Publications in the Biological Sciences

The transition of hominins to a largely meat-based diet ~1.8 million years ago led to the exploitation of other mammals for food and resources. As hominins, particularly archaic and modern humans, became increasingly abundant and dispersed across the globe, a temporally and spatially transgressive extinction of large-bodied mammals followed; the degree of selectivity was unprecedented in the Cenozoic fossil record. Today, most remaining large-bodied mammal species are confined to Africa, where they coevolved with hominins. Here, using a comprehensive global dataset of mammal distribution, life history and ecology, we examine the consequences of “body size downgrading” of mammals over ...

Betting & Hierarchy In Paleontology, Leonard Finkelman

Faculty Publications

In his Rock, Bone, and Ruin: An Optimist’s Guide to the Historical Sciences, Adrian Currie argues that historical scientists should be optimistic about success in reconstructing the past on the basis of future research. This optimism follows in part from examples of success in paleontology. I argue that paleontologists’ success in these cases is underwritten by the hierarchical nature of biological information: extinct organisms have extant analogues at various levels of taxonomic, ecological, and physiological hierarchies, and paleontologists are adept at exploiting analogies within one informational hierarchy to infer information in another. On this account, fossils serve the role ...

Crossed Tracks: Mesolimulus, Archaeopteryx, And The Nature Of Fossils, Leonard Finkelman

Faculty Publications

Organisms leave a variety of traces in the fossil record. Among these traces, vertebrate and invertebrate paleontologists conventionally recognize a distinction between the remains of an organism’s phenotype (body fossils) and the remains of an organism’s life activities (trace fossils). The same convention recognizes body fossils as biological structures and trace fossils as geological objects. This convention explains some curious practices in the classification, as with the distinction between taxa for trace fossils and for tracemakers. I consider the distinction between “parallel taxonomies,” or parataxonomies, which privileges some kinds of fossil taxa as “natural” and others as “artificial ...

Diatom-Inferred Records Of Paleolimnological Variability And Continental Hydrothermal Activity In Yellowstone National Park, Usa, Sabrina Brown

Dissertations & Theses in Earth and Atmospheric Sciences

Fossil diatoms were used to reconstruct paleoclimatic and hydrothermal conditions in Yellowstone National Park. First, an extensive literature review summarizes the current state of knowledge about eukaryotic organisms characteristic of continental hydrothermal environments. Eukaryotes in hydrothermal systems can live at extremes of acidity (pH 9.0), and at moderately high temperatures (<62 >^○C). Silicate and carbonate precipitation in continental hydrothermal environments is mediated by eukaryotic organisms, which are important members of biofilm communities.

A case study of alkaline-chloride sinter deposits in Yellowstone Lake and the Upper Geyser Basin inferred in-situ diatom growth rather than post-depositional accumulation of valves settling from the ...