Paleontology Commons^™

Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard

Theses and Dissertations

The Starkville Quadrangle is a hotspot for geological research. The Late Cretaceous is represented by the Demopolis Formation in the northeast corner of the quadrangle, followed by the Ripley Formation, and the Prairie Bluff Formation. The K-Pg boundary is exposed in the quadrangle, and the remarkable paleontology is of global importance. The Clayton Formation is the first Paleocene unit. Where the Clayton Formation channel sands are in contact with the underlying Prairie Bluff Formation, springs occur. Springs were a rare source of water in the Black Prairie and spurred the settlement of the area over 10,000 years ago. The Paleocene …

Fossil Mammals From Hickory Tree Cave, Sullivan County, Tennessee, Alexis Rivera

Electronic Theses and Dissertations

Hickory Tree Cave, also known as Big Spring Cave, is located in the southern Appalachians and is known for fossils that are considered to be Quaternary in age. Fossil mammals were identified and assigned to the lowest taxonomical level possible. Most remains are fragmented or digested and it seems likely that various taphonomic processes are responsible for the resulting assemblage. The site lacks the extreme boreal component of Pleistocene cave faunas in the region (e.g. Baker Bluff Cave), with most reported taxa inhabiting Appalachian deciduous forest environments in North America today. While the presence of tapir (Tapirus sp.) …

Sub-Recent Microfauna Within Allogenic Sediments At The Bottom Of A Deep Cave, Njemica (Biokovo Mt., Croatia), Tomislav Kurečić, Valentina Hajek Tadesse, Lara Wacha, Marija Horvat, Nina Trinajstić, Ivan Mišur

International Journal of Speleology

Clastic sediments deposited at the bottom of the vertical, nearly 1000 m deep Njemica Cave (Biokovo Mountain, Croatia) were analysed. Owing to the vertical morphology of the cave, the occurrences of clastic sediments are sparse. Small, up to decimetre-thick, undisturbed sediment accumulations situated near the siphon lake revealed interesting palaeontological and mineralogical data. These data are used as a useful proxy for discussing depositional processes, the provenance of the sediments and paleo-habitats of the subterranean fauna.

The sub-recent assemblages of ostracods were discovered within the sediment, and they were shown to be correlative to the known endemic species in the …

Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine

Geoscience Faculty Publications

Ecosystem structure—that is the species present, the functions they represent, and how those functions interact—is an important determinant of community stability. This in turn a􀀀ects how ecosystems respond to natural and anthropogenic crises, and whether species or the ecological functions that they represent are able to persist. Here we use fossil data from museum collections, literature, and the Paleobiology Database to reconstruct trophic networks of Tethyan paleocommunities fromthe Anisian and Carnian (Triassic), Bathonian (Jurassic), and Aptian (Cretaceous) stages, and compare these to a previously reconstructed trophic network from a modern Jamaican reef community. We generated model food webs consistent with …

A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset

Honors Theses

The Maastrichtian-age Blue Springs locality of the Coon Creek Member of the Ripley Formation is known for abundant, well-preserved marine fossils, including many genera of microfossils, bivalves, gastropods, decapods, cephalopods, actinopterygians, and other vertebrate organisms. This research contributes to the understanding of the paleontology of the site, as well as the changing paleoenvironmental conditions of the beds throughout deposition.

This project analyzed bulk material collected in 2021 from three fossiliferous beds at Blue Springs: the Lower Corbula Bed (Bed C), the Pebble Bed (Bed G), and the Exogyra-Pycnodonte Bed (Bed J). Unconsolidated material from Beds C and J was processed …

Faunal Comparison And Analysis Of The Blufftown Formation-Cusseta Sand Contact At Hannahatchee Creek, Georgia, Seth Fradella

Honors Theses

The origin of fossil material in the highly fossiliferous bed above the Upper Cretaceous (Campanian) Blufftown Formation-Cusseta Sand contact at Hannahatchee Creek, Georgia, has long been a subject of scientific curiosity; however, no research has yet been conducted to specifically investigate discrepancies between the fossil assemblages of the upper Blufftown Formation and the basal Cusseta Sand, which overlies it unconformably. In the most recent published hypothesis, Case and Schwimmer (1988) propose that the basal Cusseta Sand contains a mixture of original fauna as well as material reworked and redeposited from the underlying Blufftown Formation, resulting in a lag deposit above …

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

Dissertations & Theses in Earth and Atmospheric Sciences

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 …

Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores

Electronic Thesis and Dissertation Repository

The presence of eukaryotic life during the early Paleoproterozoic has been a matter of debate because well-preserved fossils older than 1.8 Ga rarely exhibit eukaryotic cellular microstructures. In this study, microfossils from the 1.9 Ga Gunflint Chert were studied using the extended-focal-depth imaging technique, combined with scanning electron microscopy, resulting in recognition of three types of large (10–35 μm diameter) complex unicellular bodies (CUBs) and one type of “multicellular body” (< 50 μm diameter). The CUBs show the following eukaryotic cyst-like structures: (1) radially arranged internal strands similar to those in some acritarchs and dinoflagellates; (2) regularly spaced long tubular processes, stubby pustules, and/or robust podia on the cell surface; (3) reticulate cell-wall sculpturing such as pits, ridges, and scale-like ornaments; and (4) internal bodies that may represent membrane-bounded organelles. These morphological features provide strong evidence for the presence of protists in the late Paleoproterozoic.

Among the three types of CUBs from the Gunflint microbiota, a new species, Germinosphaera gunflinta sp. nov., was recognized. This species has the diagnostic characteristics of Germinosphaera, such …

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 …

Stable Carbon And Oxygen Isotopes Of Early Silurian Pentameride Brachiopods From Québec, Ontario, And Nunavut, And Paleoenvironmental Implications, Jordan N. Siewnarine

Electronic Thesis and Dissertation Repository

Analysis of low-Mg calcite brachiopod shells for δ¹⁸O and δ¹³C signatures provide quantitative independent geochemical data for paleoenvironmental interpretations. We analyzed 59 brachiopod shells from lower Silurian carbonate rocks of Anticosti Island, the Hudson Bay Lowlands and Niagara regions for spaciotemporal isotopic trends for the early Silurian. Screening tests using scanning electron microscopy, cathodoluminescence and trace element analysis demonstrate exceptional preservation, suggesting retention of primary isotopic values.

δ¹³C and δ¹⁸O values of shells range from 0.2‰ to 2.9‰ and -6.9‰ to -4.3‰ (VPDB), respectively. Temporally, increases in δ¹³C and δ …

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 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 …

The Effects Of Hybridization On Skeletal Morphology In Two Closely Related Populations Of Rhesus Macaques (Macaca Mulatta): A Geometric Morphometric Approach, Cody Zachery Schumacher

Theses and Dissertations

Precise identification and classification techniques are vital for the field of paleoanthropology to ensure that hominin fossilized remains are labeled accurately. The morphology of extinct hominin specimens will typically be compared to extant nonhuman primate species because of how closely related they are phylogenetically. Observable similarities in their morphological variation can be examined to infer which traits may be a result of evolution and this can update our understanding of their evolutionary relationships. The genus Macaca displays a level of morphological variation that is similar to that seen in the genus Homo, therefore macaques can be used as an analogous …

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 …

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 …

Terrestrial Perspective On The Formation, Evolution, And Detection Of Zeolites In Lacustrine Environments On Early Mars, Gayantha Roshana Loku Kodikara

Theses and Dissertations

This study evaluates the possible formation and evolution mechanisms of zeolites on early Mars with possible explanations for their limited detections using Earth analogs. This study focuses on the formation of zeolites in the closed basin lakes where the largest relatively pure concentrations of natural zeolites are found on Earth. Five working hypotheses were formulated to explore the limited detection of zeolites in closed basin lakes on Mars and different styles of scientific reasoning with suitable examples were used to test the independent, converging lines of inquiry. Zeolites may not be identifiable in certain locations on Mars using orbital data …

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 …