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Full-Text Articles in Paleobiology

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons Jul 2026

Minerals Rock!: Improving Audience Engagement And Interest In Stem Through Enhancement Of The In-Person And Online Mineral Collection At Ursinus College, Juliette Lyons

Environment and Sustainability Summer Fellows

Museums are a vital source of educational resources for the general public. They provide information on a variety of topics and disciplines and encourage visitors to be excited about and engaged in learning something new. As we work to comprehend key topics such as climate change, it is especially important for the broader public to better understand science, including geology. While the geological collection at Ursinus, Pieces of Earth’s History, is not in a museum, implementing methods that museums use can improve the reception of the collection. Through the application of research gathered through articles, journals, books, and talking with …


Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad Jun 2026

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad

University Honors Theses

Throughout the Phanerozoic, one of the most successful phyla of marine invertebrates has been Echinodermata. Echinodermata was particularly successful throughout the Paleozoic, with class Crinoidea making up a majority of occurrences. The proportion of echinoderm occurrences that are crinoids declined massively at the end of the Permian and continued to decrease into modern day, never fully recovering. One of the factors thought to have been so important for crinoid success in the Paleozoic and their decreasing success throughout geologic time has been their propensity for success in shallow-marine environments, though crinoids also exist within deep-marine environments. This study seeks to …


On The Paleontology Of Belize, Alson Ovando May 2026

On The Paleontology Of Belize, Alson Ovando

Electronic Theses and Dissertations

Paleontology can be considered an underrepresented and emerging area of science in Belize. A primary aim of this thesis is to provide a background of paleontology in Belize and present the first comprehensive study of Quaternary vertebrate fossils known from the country. Quaternary fossil sites across Belize include caves, rivers, and sinkholes. In addition to reviewing and assessing material from known sites, this thesis presents new information and discoveries that were made while investigating Belize’s Quaternary fossil record. This thesis also includes a geospatial model depicting ecoregions in Belize during the last glacial maximum. Overall, the results presented here demonstrate …


Paleo-Environmental Change In Deer Lagoon, Whidbey Island Interpreted From Diatoms And Lithology, Lourdes Garcia Jan 2026

Paleo-Environmental Change In Deer Lagoon, Whidbey Island Interpreted From Diatoms And Lithology, Lourdes Garcia

All Master's Theses

Puget Sound is a densely populated, tectonically active area that can be affected by earthquakes from local crustal faults and the Cascadia subduction zone capable of producing abrupt coseismic subsidence. Tidal wetlands are particularly sensitive to abrupt changes because they are depositional environments that reside at sea-level and their lithology and ecological communities are strongly controlled by elevation within the tidal frame. As a result, coseismic subsidence can disrupt established environmental gradients and leave distinguishable signatures preserved within the stratigraphy, like tidal mud directly over peat deposits. These preserved records provide an opportunity to reconstruct past earthquakes and associated relative …


The Petm: A Window Into Earth's Future Climate, Jacalyn M. Wittmer Malinowski May 2025

The Petm: A Window Into Earth's Future Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

The Paleocene-Eocene Thermal Maximum (PETM) is not just an event that occurred in Earth’s distant past (~55 million years ago) but is a crucial lesson for today’s meteoric climate change. The PETM offers a historical parallel of rapid flux of greenhouse gases into the atmosphere that caused global warming, ocean acidification, dramatic changes in weather, and extinctions. This global warming event was the result of 20,000 years of “rapid” warming (in geological terms) however, we are experiencing rates of warming that are 5-10x higher than PETM levels. We are not experiencing rapid warming today, in comparison to the past, we …


The Human Legacy: Agriculture, Civilizations, Strife, And Pandemics Changing Our Climate, Jacalyn M. Wittmer Malinowski May 2025

The Human Legacy: Agriculture, Civilizations, Strife, And Pandemics Changing Our Climate, Jacalyn M. Wittmer Malinowski

Climate Change and the Individual, 2025-26

For most of human history, climate has shaped our lives, while our influence on it remained minimal. However, the notion that early humans had no measurable impact on the climate before industrialization is inaccurate. Early in human history, activities – such as the rise of agriculture, the growth of civilizations, periods of conflict, and pandemics – altered greenhouse gas levels in the atmosphere. These changes contributed to significant periods of climate change long before the burning of fossil fuels set us on the path to today’s global climate crisis.


Evaluating Biotic Effecrs Associated With The Paleocene-Eocene Thermal Maximum In Mississippi And Alabama: A Palynological And Biostratigraphic Study Of Amoco's Legacy Samples, Sarah Fortin Bancroft Mar 2025

Evaluating Biotic Effecrs Associated With The Paleocene-Eocene Thermal Maximum In Mississippi And Alabama: A Palynological And Biostratigraphic Study Of Amoco's Legacy Samples, Sarah Fortin Bancroft

LSU Master's Theses

The Paleocene-Eocene Thermal Maximum (PETM) was a ~200 ka period of rapid global warming in the earliest Eocene (~56 Ma) involving a roughly 7 °C rise in atmospheric and sea-surface temperatures. The Gulf of Mexico Wilcox Group contains very well-preserved terrestrial and deltaic sediments that contain exploitable hydrocarbons . The Wilcox Group’s Paleocene Tuscahoma and Eocene Hatchetigbee Formations have been roughly dated with calcareous and planktonic foraminiferal assemblages by AMOCO; however, the precise ages of these formations, their palynological assemblages, and their paleo-depositional geosystems are an area of active research.

Through a high-resolution palynological analysis, this study assesses the depositional …


Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka Jan 2025

Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka

Theses and Dissertations--Earth and Environmental Sciences

The Sierra Nevada essentially serve as the headwaters of California, providing crucial freshwater to the state through seasonal snowmelt. This water supply is threatened by climate change in complex ways that are not fully understood. Geological records provide a valuable source of information on how the hydrology, limnology, and ecology of the Sierra Nevada region has responded to climate changes of the past. This dissertation presents new sedimentary and paleoecological research from Mono Lake and Convict Lake (Mono County, California) and aims to shed light on environmental changes in the eastern Sierra Nevada from ~16 ka to present.

At Mono …


Distribution And Tooth Morphoguilds Of Mosasaurids (Squamata) Of The Campanian Western Interior Seaway With Implications For Controls On Mosasaur Paleobiogeography, Alec Zaborniak Jan 2025

Distribution And Tooth Morphoguilds Of Mosasaurids (Squamata) Of The Campanian Western Interior Seaway With Implications For Controls On Mosasaur Paleobiogeography, Alec Zaborniak

Master's Theses or Doctor of Nursing Practice

The Western Interior Seaway (WIS) of North America is well known for its mosasaurid squamate diversity, particularly during the Campanian of the Late Cretaceous. Mosasaurid diversity has historically been examined at a fine scale, with many studies investigating the faunal composition of specific assemblages; however, studies focusing on mosasaur communities within the Western Interior Seaway during specific Ages are currently lacking. Mosasaur tooth morphology has also been extensively studied, with tooth characteristics commonly being used as phylogenetic characters. However, many studies examining mosasaur communities and tooth morphology have been focused on broader spatiotemporal or phylogenetic scales. This study investigates the …


A Histological Survey Of A Large, Sub-Adult Tylosaurus Nepaeolicus With Implications On The Validity Of Tylosaurus Kansasensis, Carson Cope Jan 2025

A Histological Survey Of A Large, Sub-Adult Tylosaurus Nepaeolicus With Implications On The Validity Of Tylosaurus Kansasensis, Carson Cope

Master's Theses or Doctor of Nursing Practice

Tylosaurus nepaeolicus is a basal, medium-sized tylosaurine mosasaur that lived during the late Coniacian and early Santonian in the Western Interior Seaway. Despite being a well-studied species, there is debate over whether Tylosaurus kansasensis represents the juvenile form of T. nepaeolicus, or if the two species are distinct. Osteohistology can determine organism age at time of death and can be used to help resolve this debate and provide a better understanding of the growth of T. nepaeolicus. Thin-sections were taken from a humerus, rib, and vertebra of a single individual (FHSM VP-2209). All thin-sections show primarily parallel-fibered cortical …


A Paleobiological And Paleoecological Analysis Of Mississippian Trilobites With Segmentation Abnormalities, April Catherine Cerami Jan 2025

A Paleobiological And Paleoecological Analysis Of Mississippian Trilobites With Segmentation Abnormalities, April Catherine Cerami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Trilobites are a well-preserved group of arthropods, with a fossil record extending from the Cambrian to the end of the Permian. Abnormalities, such as injuries or teratological defects, have been observed and described in multiple individuals, although investigating how these abnormalities occur in populations has been largely overlooked.

One possible cause of abnormalities in marine arthropods is heavy metal pollution. Such metals can leave individuals more susceptible to teratological deformities and injuries, interfering with the molting and healing process. Here, methods for analyzing elemental composition and preservation of the trilobite cuticle were refined, finding that 30 μm thin sections are …


Tales In The Teeth: Using Isotopic Analysis To Understand The Paleoecology And Social Behavior Of Brontotheres Of The Intermountain Basins During The Middle Eocene, John Michael Michalski Aug 2024

Tales In The Teeth: Using Isotopic Analysis To Understand The Paleoecology And Social Behavior Of Brontotheres Of The Intermountain Basins During The Middle Eocene, John Michael Michalski

All Graduate Reports and Creative Projects, Fall 2023 to Present

Isotopic analysis has been a common practice used in paleontology to study ancient ecosystems, and the lives of animals therein. Oxygen isotopic analysis is of particular importance not only because of its use in studying paleoecology, diet, and migration, but also its use in studying mountain elevation, and its impact on ancient ecosystems. I use stable oxygen isotopic analysis to study the habits and ecology of brontotheres from intermountain basins surrounding the Uinta Mountains of Utah and Wyoming, USA. I studied the oxygen isotopes from 16 fossil specimens of teeth, most of which belonged to brontotheres, including the genera Palaeosyops …


Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry May 2024

Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry

School of Earth & Environment Departmental Research

Previous studies on microtaphonomy have identified multiple types of organic microstructures in fossil vertebrates from a variety of time periods and past environmental settings. This study investigates potential taphonomic, paleoenvironmental, and paleoclimatic controls on soft tissue and cellular preservation in fossil bone. To this end, fifteen vertebrate fossils were studied: eight fossils collected from the Oligocene Sharps Formation of the Arikaree Group in Badlands National Park, South Dakota, and seven fossils from formations in the underlying White River Group, including the Oligocene Brule Formation of Badlands National Park, and the Eocene Chadron Formation of Flagstaff Rim, Wyoming; Toadstool Geologic Park, …


Analyzing The Shark Paleoecology Of Coastal Georgia From The Miocene And Pliocene Epochs, Joshua Lee Clark, Benjamin Angalet Dec 2023

Analyzing The Shark Paleoecology Of Coastal Georgia From The Miocene And Pliocene Epochs, Joshua Lee Clark, Benjamin Angalet

Georgia Journal of Science

The field of shark paleoecology often yields indecisive conclusions based on the limited fossilization of their anatomical structures, with the exception of their teeth. The majority of the Atlantic coast has been studied regarding the presence of certain prehistoric shark species from the Miocene, Pliocene, and Pleistocene epochs. However, information pertaining to the Georgia coast and understanding its potential community structure is relatively understudied. This study was conducted in which thousands of fossil shark specimens and subsequent marine fauna were collected from dredge spoils created by the US Army Corps of Engineers (USACE): Savannah District. A total of 5,127 fossil …


Field Guide To Big Bone Lick, Kentucky: Birthplace Of American Vertebrate Paleontology, Glenn W. Storrs, H Gregory Mcdonald, Eric Scott, Robert A. Genheimer, Stanley E. Hedeen, Cameron E. Schwalbach Oct 2023

Field Guide To Big Bone Lick, Kentucky: Birthplace Of American Vertebrate Paleontology, Glenn W. Storrs, H Gregory Mcdonald, Eric Scott, Robert A. Genheimer, Stanley E. Hedeen, Cameron E. Schwalbach

Special Publication--KGS

Big Bone Lick is the birthplace of vertebrate paleontology in the Western Hemisphere and has a long and celebrated history in the exploration of the American colonial frontier and of the early United States. Notable European scientists of the 18th century such as Buffon, Cuvier, and Hunter discussed the fossils found there. Prominent Americans of the time, such as Boone, Washington, Franklin, and Jefferson are also part of the site’s history. It is the type locality for several extinct late Pleistocene megafaunal mammals, most notably the iconic American Mastodon, who were attracted to the area by salt licks dictated by …


Identifying Taphonomic Distribution Patterns At The Gray Fossil Site, Shawn Haugrud May 2023

Identifying Taphonomic Distribution Patterns At The Gray Fossil Site, Shawn Haugrud

Electronic Theses and Dissertations

Since the early days of the discovery of the Gray Fossil Site (GFS), meticulous efforts to preserve the spatial data were a priority. Direct surveying of fossils prior to recovery, as well as grid mapping the site, provided relative spatial data within a square meter. Such efforts meant that even fragments and microfossils, recovered during the screening operations and eventual concentrate picking, maintained some spatial data. Available spatial data are used to identify smaller deposits within the greater system, as well as non-random distribution patterns among a number of GFS taxa. Patterns are particularly pronounced in the large-bodied taxa, Teleoceras …


Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie Apr 2023

Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie

LSU Master's Theses

Fungi play key and specific roles in ecosystems, specifically as many have restricted geographic distributions, known host/substrate preferences, and are important local environmental indicators due to their short dispersal distances. This study of fossil fungi from a time interval of pronounced global warming, the Miocene Climatic Optimum (MCO), allows analysis of fungal response to an analogue for future climate change scenarios. The research presented herein is part of a larger project, Fungi in a Warmer World (FiaWW), which is using globally-distributed sediment samples to provide foundational information on fungal community distribution patterns and will provide the first fungi-based climatological reconstructions …


The Anatomy And Phylogeny Of A New Large Plioplatecarpine Mosasaur From The Campanian Bearpaw Shale Of Montana (Usa), Richard A. Carr Jan 2023

The Anatomy And Phylogeny Of A New Large Plioplatecarpine Mosasaur From The Campanian Bearpaw Shale Of Montana (Usa), Richard A. Carr

Master's Theses or Doctor of Nursing Practice

In 2018, a large and associated plioplatecarpine mosasaur skull, pectoral girdle, and rib cage, whose total body length may have exceeded five meters, was uncovered in the Late Campanian Bearpaw Shale of Northeast Montana (USA). Phylogenetic analysis of this specimen, MOR 10855, recovers this individual as a basal member of the genus Plioplatecarpus. This specimen, is unique in that it is estimated to be nearly twice the size of any of the other species of Plioplatecarpus found in the Western Interior Seaway during this part of the Cretaceous. While the included phylogenetic study suggests MOR 10855 represents a new …


Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill Jan 2023

Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill

Master's Theses or Doctor of Nursing Practice

Avian fossil records from across the Caribbean (Greater and Lesser Antilles) demonstrate higher avian diversity prior to extinction events due to climate change at the end of the Pleistocene and human impact across the Caribbean throughout the Holocene. Amazon parrots (Amazona) are a diverse genus of New World parrots found throughout Central and South America, as well as the Caribbean. Their phylogeny and evolutionary history, specifically for Caribbean species, has been debated in terms of source areas in Central and South America and the timing of and number of colonization events to different islands that preceded diversification into …


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 Oct 2022

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 Research

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 …


Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith Aug 2021

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …


Determining Biostratigraphy And Correlation Using Color Alteration Index And Lithofacies Of Conodonts In The Edinburg Formation, Central Virginia, Lauren Showalter May 2021

Determining Biostratigraphy And Correlation Using Color Alteration Index And Lithofacies Of Conodonts In The Edinburg Formation, Central Virginia, Lauren Showalter

Senior Honors Projects, 2020-current

Conodont species, CAI and lithofacies analysis are used as methods of correlation to determine the relative age, depositional environment, and post depositional burial history of the Edinburg Formation in central Virginia. Samples collected for conodont microfossils yielded faunas of Baltoniodus sp. or Amorphognathus sp., Periodon grandis and Protopanderodus liripipus from a site near Luray and Drepanoistodus suberectus, Plectodina sp., Protopanderodus liripipus, Oistodus sp., Phragmodus undatus, Erismodus radicans and Panderodus gracilis from a site in Harrisonburg. The species supports a Late Ordovician (Late Sandbian age). Conodonts from both sites have a CAI of 4-5, indicating post-depositional heating of …


Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt May 2021

Terrestrial Soldier Crab (Coenobita Clypeatus, Fabricius 1787) And Cerion Spp. (Röding 1798) Shell Relationship On San Salvador Island, Bahamas, Harley Hunt

Biology Theses

The Caribbean terrestrial soldier crab, Coenobita clypeatus(Fabricius 1787), coexist and utilize the shells of numerous species of land and marine gastropods. Soldier crabs rely on gastropod shells for protection as the crabs have a soft abdomen, leaving them vulnerable for predation and desiccation, threatening their survival. This creates a strong pressure to obtain well-fitting shells that provide adequate protection against water loss. Cerion of Röding (1798) shells are one of the most commonly used shells among living colonies of C. clypeatuson San Salvador Island. This study is interested in the frequency of shell use by C. clypeatus crabs …


Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan May 2021

Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

An Apatosaurus sp. locality from Dinosaur National Monument designated DNM-15 was excavated in 1985, and associated with two Allosaurus teeth and one Ceratosaurus tooth that were near one of the caudal vertebrae. The Ceratosaurus tooth was buried between an overlying rib and that same caudal vertebra. The caudal vertebrae of the DNM-15 Apatosaurus were intact and articulated, but the anterior skeleton was mostly absent, with a row of articulated sacral vertebrae in close association with a femur. Two other Allosaurus teeth were reported near the preserved ilium of the Apatosaurus, but they could not be located in the collections. …


Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey, Corinne Myers, Jason Moore, Louis Scuderi Apr 2021

Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey, Corinne Myers, Jason Moore, Louis Scuderi

Earth and Planetary Sciences ETDs

Multiple linear regression was used to determine the relationships between diversity-independent factors (i.e., abiotic, climatic) 2, 5, and 10 Myrs-prior to the most elevated Phanerozoic extinctions. We constructed five abiotic variables from Phanerozoic proxy records1–5 to compare to extinction rates: mean temperature, temperature instability, carbon cycle instability, continental weathering rates, and habitat instability. All three models were statistically significant (P < 0.05) and explained > 70% of the variation in Alroy’s6 three-timer generic extinction rates. However, the 2 Myr-prior model explained the most variance in extinction rates and had the most predictive power, based on adjusted and predictive R2 (~ 72% and 41%, respectively). Carbon …


Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey Apr 2021

Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey

Earth and Planetary Sciences Faculty and Staff Publications

Multiple linear regression was used to determine the relationships between diversity-independent factors (i.e., abiotic, climatic) 2, 5, and 10 Myrs-prior to the most elevated Phanerozoic extinctions. We constructed five abiotic variables from Phanerozoic proxy records1–5 to compare to extinction rates: mean temperature, temperature instability, carbon cycle instability, continental weathering rates, and habitat instability. All three models were statistically significant (P < 0.05) and explained > 70% of the variation in Alroy’s6 three-timer generic extinction rates. However, the 2 Myr-prior model explained the most variance in extinction rates and had the most predictive power, based on adjusted and predictive R2 (~ 72% and 41%, respectively). Carbon …


Ecological Controls On The Campanian Distribution Of Hesperornis (Aves: Hesperornithiformes) In The Western Interior Seaway, Blake Chapman Jan 2021

Ecological Controls On The Campanian Distribution Of Hesperornis (Aves: Hesperornithiformes) In The Western Interior Seaway, Blake Chapman

Master's Theses or Doctor of Nursing Practice

The epicontinental Western Interior Seaway (WIS) of Late Cretaceous North America provided a unique marine habitat for cephalopods, fish, marine reptiles, and the foot-propelled diving seabird Hesperornis. While several predator-prey relationships among Hesperornis or other hesperornithiforms and other WIS animals have been hypothesized based on gut contents, bite marks, and coprolites/colonites, ecological relationships have not been quantitatively tested. Paleontological species distribution modeling (SDM) studies have focused on extinct non-marine taxa and marine invertebrates, with only two marine vertebrate studies of extant taxa. Here, two SDM methods were used to test the influence of vertebrate faunas, sedimentary rock type, paleogeography, …


Manus Descriptions Of An Undescribed Mastodon From The Latest Miocene-Earliest Pliocene Gray Fossil Site, With Comparisons To Other North American Proboscidean Taxa, Brenna Hart-Farrar Dec 2019

Manus Descriptions Of An Undescribed Mastodon From The Latest Miocene-Earliest Pliocene Gray Fossil Site, With Comparisons To Other North American Proboscidean Taxa, Brenna Hart-Farrar

Electronic Theses and Dissertations

A detailed morphological description of a proboscidean manus from the Gray Fossil Site (GFS), Gray, Tennessee is provided. Manus elements from an American mastodon (Mammut americanum), a Britt’s shovel-tusker (Amebelodon britti), an undescribed small gomphothere species, and a Columbian mammoth (Mammuthus columbi) are used for comparisons. Linear measurements indicate proportional differences between the GFS mastodon and other proboscidean taxa ranging from the Hemphillian to Rancholabrean land mammal ages. Possible pathologies are also described. The purpose of this study is to determine how the GFS mastodon differs in manus morphology and locomotion from different proboscidean …


Eutherian Biogeography During The Puercan North American Land Mammal Age (Paleocene, Earliest Danian): Problems And Potential Solutions, Jason Sterling Silviria Jul 2019

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, …


Constraining The Oxygen Values Of The Late Cretaceous Western Interior Seaway Using Marine Bivalves, Camille H. Dwyer Jul 2019

Constraining The Oxygen Values Of The Late Cretaceous Western Interior Seaway Using Marine Bivalves, Camille H. Dwyer

Earth and Planetary Sciences ETDs

The Western Interior Seaway (WIS) remains an oceanographic enigma, including its circulation, similarity to the open ocean, and the fidelity of geochemical proxies to reconstruct paleoenvironments. Across the late Campanian and early Maastrichtian I test whether: 1) the WIS had unique δ18OVPDB compared to other marine settings, 2) increasing oceanographic restriction changed the stable isotope composition, and 3) biases, e.g., taxonomy or diagenesis, influenced stable isotope compositions. Results indicate distinct δ18OVPDB in the WIS compared to other marine settings. δ18OVPDB values were stable through time, suggesting insignificant oceanographic restriction and a …